I’d argue that the only community that matters is the one you make for yourself via guilds and in game friends. Saying WoW’s current player base is a “community” is just using the term in its loosest sense. You could take 10 current players who all enjoy the game equally but whose paths would never really cross because they all enjoy different ways of playing the game (and half of them wouldn’t get along or would prefer to just ignore everyone).
There are plenty of decent people and there’s no shortage of assholes. If anything, bringing more players to the game would help increase the pool of decent people that you can actually form a real bond with. Yes, there would also be more assholes, but unlike a game that is predominately queue based, in WoW you have better options for picking and choosing who to play with.