Large independent living and assisted living communities are their own little society. The women outnumber the men by a huge number (due to mortality). My wife and I are a few years apart in age. We worked it out so we will both live to about the same time!
One dynamic of these communities is that although they are marketed to the elder as a place to meet new friends, it is often easier said than done. If your parent or friend is thrown into a situation with a bunch of other seniors that does not necessarily mean that they will make friends. The residents are from varied socioeconomic levels, cultures, and environments, and they don’t necessarily have things in common. Commonality is what binds friendships.
Your relative or friend will likely find new friends after a short while, but remember that the adjustment period is just as tough for seniors as it would be for a kid who goes to a new school or for a person who moves to a new city. They are moving into a new place that has its own established social life, and it will take some time for them to feel comfortable and fit in.
So be aware that it will be quite difficult for your elder to adapt and make friends. The good news however, is that other new residents are in the same situation.