Yes, I was going to suggest just that. Please follow up with the Alzheimer's Association. Also, please know that it's possible further discussions with your parents are just going to increase their stress and yours. I know it's tougher because cognitively your father is in better shape than your mom, but with persons with dementia, talking about things before they happen (and trying to get them to accept changes) actually makes it worse for all involved. Sometimes the changes just have to be made.
I speak from 9 years of experience working with seniors, about half of whom lived in the "Meadow Wing" of the assisted living. They "live" in the immediate present and the past, but cannot really comprehend reality when it comes to their futures. Even good news, if it's about the future, can be a stress point (because if it's something like "grand kids will be visiting tomorrow!" their sense of time is not linear anymore and they will literally sit staring out a window for the grand kids for the next 24 hours. And feel very agitated when they don't show).
Just being their daughter doesn't make you qualified or capable of being the caregiver. Often it makes you less qualified because objectivity goes out the window. The times I have been in that role it was made clear to me that if I was exhausted and/or miserable it was not doing the patient or me any good at all. Better to be the one that brings cheer and good company than the one that bugs them about taking their meds.
And this. Laura is so right.
And you're the kind of loving daughter who wants to make sure everyone agrees with everything and you have total buy-in from them before any changes are made. I get that. But I think you'll drive yourself mad without some professional guidance from AA or a social worker/ombudsmen. And it might be easier for your dad to swallow the news if it's coming from a disinterested person outside of the family.