It depends on their needs. Seniors in the 55-70 age group in good health wouldn't need what the 65+ would need if health issues were prevalent. I'm 61 in good health and plan to work many more years. My housing needs have changed due to the kids leaving and with Texas taxes who needs to pay 15k/yr. I wanted a one story, efficient floorplan, golf course, updated. Those were my criteria if that tells you anything.
Each buyer is different. Being they have made it to this age they kinda know what they want. Just ask.
Believe it or not, the national trend for boomers is to sell and move to rental. When surveyed, boomers are tired of the all that comes with real estate ownership and have started moving into rental living. For the ones who like everything that goes with ownership, the ability to age in place is a key factor. Boomers hate the term age-in-place but the idea is key.
You can find dozens of articles on the move to rental. Below is just one example.