More Towns
After building up some better social features, it opens up the door to have some more interesting towns other than just The Tower. If strangers can actually effectively communicate, then it would be possible to try and theme certain areas around specific activities, interests, or goals.
After all, part of the MMO experience is feeling like you’re part of a larger world. When it’s instead just a small handful of people – that you can’t even easily talk to – crammed into the same space for years on end, the world doesn’t feel all that big.
Destiny 1 sort of did this, but the social areas felt tacked on parts of major expansions and didn’t feel like they were anything other than just different looking Towers.
Why not have a space designed around PvP, Raids, socializing, etc.? That way players can congregate and possibly meet new people with similar in-game interests or work together to get things done with a stranger instead of being alone most of the time.