[2021] AC Black Flag Social Features

Can anyone tell if the social features arw still alive?
I'm playing on PC but startet a new Game on PS4 and i want to have the gouvanour Outfit. But i need to find it in a social chest. I think i need them for a trophy too, but i'm not sure.
Are these still spawning? I already read that i don't have to have any friend in my friendslist playing AC4 to find them but how is this system working exactly?
Are these Events pure random? Would be good to know how this works. Is the chance higher the more players are on the same server or is it not important how many players are online at the same time? I talk not about friends, i know they can share those events. I talk about playing alone and try to find one of these chests.

Thanks for your help.