So one of the big complaints people have about LFG/LFR is that you are running with complete randos each and every time. This makes it harder to build community relationships.
I was thinking, perhaps they could add a "like" (yeah, lets not call it a like button, but) button of sorts for running group finder things, be it world bosses, random instances, LFR, island expeditions, questing, or whatever else uses the tool....heck, even just in random moments around the world or mythics or raiding pug groups you can do it too. You don't commit to being their "friend" or having to actively seek them out later...you just have an option to put them into a pool that you would not be opposed to seeing them again.
Say you run an instance, and you find a really good healer...or you joke around a bit and get a bit of a vibe that you might get along with a player(s). At the end you get a chance to thumbs up that player...that data does not preclude players you do not choose from being in your group in the future.... and only impacts you and does not lower or raise anyone elses status in the game.
With that bucket that you start filling up with players, the game automagically filters them into your next LFG, LFR, Battleground or whatever thing you queue into when they are also in said queue. You also see some notation/symbol of a group they are in when you are scrolling through lists of pre-made groups for pug raid groups and the like to slightly influence you in that direction. Maybe the tech can be designed so those players are more likely to show up in cities you are in...or in phased/sharded areas of the world you are in.
This is not something you will see right away.... heck, depending on how much you play you might not see much at all at first....but slowly, over time....the system will start to give you repeat experiences with players.....and due to having to randomly be doing the random things at the same time...you will start to see players that have similar play habits and times as you. This gives you a natural way to start forming a community of your choosing.
Lots of potential issues with this type of system, like what if you dont want to see a player again--the sheer size and randomness of users and what they might be doing in the game at any given time, do you do it character based -- or account based...and much more.......but I think there is something in the idea that could be a basis for a system that could help.