CAR, whether baby boomers will be looking at liquidating their houses does not matter. They are switching from one form of housing (owner) to another form of housing (renter). It doesn’t change the overall demand for shelter. Real estate investors as a supply of these shelters (again either in the form of landlord or seller) would benefit if the demand grows.
By default, the demand will grow due to new household formation. Renter affordability will slow the household formation but I don’t see it will reverse the trend.