Dad is moving to memory care facility, should he be allowed to visit his house?

NO, taking them to their house gets them really agitated and weepy. Don't do it. When they see things moved or missing or boxed up, they get upset.

Thanks, that helps to clarify what I've heard, but I needed to hear if from someone in near "real time."

Your dad needs to get acclimated to his new living arrangements and I don't think he can do that if he's visiting his old place. Transitioning into a nursing home is so difficult and leaving to visit his house will make the transition that much harder. Nothing can be gained by taking him to visit his old house except to depress your dad and make him realize what he's lost.