Can a MassHealth representative sign that a dementia patient will not return home?

Is this taking rights away when capacity is unknown? My father in law has had his licensed revoked, lives 50 miles away, the house is infested with mice, and he has gotten lost. We feel he needs long term care but he wants to live on his own with his wife. His wife has decided on long term care because he can't provide the physical care she needs now. We don't feel he'd sign the Mass Health form saying he will not return home. Mass Health is saying my husband as his authorized representative can sign it. A psychiatrist was wishy washy on his competence and told his to have him sign a power of attorney form at one of his better moments. We don't want to pursue conservatorship as they don't have enough assets to warrant the expense. Are we taking his rights away by signing for him?