My mother recently updated her will and power of attorney, and named my siblings as executors and POA. Why am I being left in the dark?

Count your blessings and let them have it all. You are finally free.

I write this with the intent of explanation, not of criticism or to add to your concerns.   But the fact that you do feel you should be involved may be the very  reason why your mother chose not to involve you.  

There may be other reasons that we or you may never know, but they may relate to confidence in your ability to handle the tasks, or to keep them private, or to interact well with your siblings.  

Or perhaps it's exactly the opposite:  your parents may feel that you've extended yourself over the years, and want to give you an opportunity to enjoy them now and after they pass w/o having to deal with the end of life and legal issues. 

Try instead to focus on the fact that she's taken care of end of life situations, and be happy that she's presumably found a solution to address them.   And cherish her for what and who she is; these times will never be repeated, you'll never have another chance, so focus on maximizing the positive aspects of your parents' remaining time and the fact that the siblings are involved, even if they haven't been for years.

My parents never discussed their decision to make my brother (middle child; I'm the eldest) their POA and executor. All three of us were on their HC proxies.

This is your parents' decision to make and they owe NO one an explanation.

It does not feel good when you have been the primary “devoted child” for your parent, and you are suddenly removed by your siblings in an underhanded manner without explanation. I experienced the same situation, and your feelings are valid. My parents already had dementia and we’re very confused when my brothers changed their documents to exclude me. I had previously quit my job and handled everything relating to their care with NO help from my two brothers, who live locally but visited 2-3 times a year. They suddenly decided that I (a well-educated career woman) could not manage the situation as well as they could. Long story short, I sought full “Guardianship” of my mom in court (which supersedes POA and HCP) and the judge granted it to me. The judge disagreed with everything my brothers said, and did not appreciate their sudden “need for control“ over her care and money when I was the only child actively involved in my parents lives. My mom now lives with me and my family- she is doing better than ever and I love caring for her. I have lots of help through the Medicaid CDPASS program... which allows you and caregivers of your choice to be compensated to care for your parent at home. Obtaining guardianship was an expensive legal process, and caring for a parent at home is very involved, and not a reasonable option for many people. That said, I want you to know I understand how hurt you feel, and your feelings are valid. You clearly love your mom and want to continue to be involved in her care. Your role (which you may actually enjoy) has been ripped away from you without good reason. It could be about financial control and may have nothing to do with your capability. You sound like a loving and devoted daughter who has your moms best interest at heart. I wish you well.

Happened to us, too. My mother-in-law announced that she changed her will after her husband died, but told us that her new lawyer said that she shouldn't show anyone her new will. My husband is her only child, and he is (or was, at least) the executor of her estate. Yeah, so, we are calling BS on that line. She has a history of lying about anything and everything, so we can never believe what she tells us.

What we think happened is that the big, impersonal church she belongs to came to her after her husband passed away and talked her into donating some huge chunk of her estate to the church when she dies. It's her money, and if she wants to bequeath a pile of cash or her house to them, that is her right. However, if they convinced her to leave everything to them, there is going to be a squabble.

She told my husband that he should destroy her old will, but he is hanging onto it in case we need it if we have to show that her original intention, before somebody got to her, was not to disinherit her only family. She is perfectly sane, except for her weird habit of making stuff up, so it's not a matter of dementia. If she ever does get dementia, it will probably be Irish dementia - she will forget everything but her grudges. ;-)

Your mother really wasn’t obligated to discuss her will with anyone. And as far as the POA, she wasn’t obligated to discuss that with anyone except those she wanted to designate as her POA. Wills and POA are both things that don’t require a family discussion & should be done by your mother’s own free will. I understand you feel left out but your mother didn’t do anything wrong, she doesn’t have to discuss these with anyone. There is only an issue here if your mother isn’t in her right mind. And if that’s the case, she shouldn’t be changing anything.

This is not a bad thing. My 94 year old mom has decided to make my only sib and me co-executors and it is going to be a nightmare after she passes. I am prepared to walk away from my inheritance, as my sibling is an all out thief and pirate. Arghhhhh.....

My parents were very old fashioned in their approach to their will. 3 boys, 3 girls--and the executors and POA's have always been the boys. OB died about 8 years ago, so the job falls to the YB's. There are 2 girls older than these brothers, but mother and dad felt that girls weren't capable of doing the job.

I didn't and don't take it personally. Mother has told me for years that her will is an open book, which it is and a boring one to boot. My 'inheritance' is so small, it's not worth mentioning. I'll probably gift it to the YB who has housed her for the last 22 years for no pay whatsoever.

My DH and I could not come to a decision about who should be our executor--in fact, I knew it should be our oldest daughter b/c she is level headed, smart, organized and unemotional. Our son is an attorney who lives in another state and is not the least bit interested in our lives. He is a hot head and if he were 'in charge' as it were, it would fracture my family.

I wanted my daughter, my DH wanted my son to do this, and I am so dang stubborn, I just held out for literally YEARS. He finally caved and now that all is said and done, he sees that the choice of our OD being the executrix is smart and wise.

Yup, Son is upset, but I don't care.

Very little, if any mention of potential elder abuse. Do you think your mother may have been encouraged (coerced) to make the changes?

Annie2019, I am glad you asked your question, as I have needed to get this story out of my mind, sad as it is, and learn to move on!
I am the oldest of 4, and when dad died 30 years ago my brother, 2nd who was the executor of his will, never read it aloud. I never questioned anything. Hind sight is 20/20 and I should have asked to read the will. Fast forward 30 years, Mom died earlier this year. Since dad's death I had been told that I was not in the will, and I never questioned that decision; it is and was my parents' money and they can do whatever they want with their money. After Mom's death, I found out I was in the will, and was getting 1/4th of everything, provided I did not question anything that my brother and sisters decided to do. As I was helping to clear out important documents, I found and kept the original will. To my shock and sadness, dad had named me as Mom's Primary Care Giver, had given me POA, and health care advisor, provided that I undertook the task once dad died; there was a 7 year waiting period. If I did nothing for 7 years, the duties would go to my brother and sister. Seven years passed after dad died, I did my yearly visits, weekly calls, but nothing special. So they took over. They paid themselves a hefty yearly salary, got control of her finances, made the house out to Mom and sister, and now want my share of the 1/4th to be split between the 3 of them.
So yes, it does happen, my dad knew those three were greedy and tried to protect Mom. She would not have died so soon as I would have watched her health; she had TIA's and sister, whom Mom was living with did not know this and was just disgusted that Mom was wetting herself in public. I am still trusting of them, I know this is bad. I now know that if my "close siblings" can cheat anyone sibling others will do the same. Husband, children and I have always lived within our means so Mom's money will help in our old age. My siblings however were so used to her money they are in financial ruin. Money makes siblings, no matter how religious they are, very greedy.
Now the healing can begin :)