If its anything like private servers, no.
People talk a lot more in Classic, and that is because there is nothing to do in the game, so people just sit in trade chat or barrens chat and post racism and memes all day.
The reason people seemed reasonable and willing to communicate was because in 2004, the gamer culture was different. Thinking the game will facilitate a full return to that is the epitome of nostalgia in my eyes, and after many many hours spent on Private servers I see the same things I see on live servers.
Build a group:
1 player joins.
2nd player joins, first one is AFK.
Player three joins, player 1 is offline with no communication.
Final player joins, another one leaves.
Finally fill with 5 attentive players, 1 of them is not making any effort to get to the dungeon.
Finally get all 5 players in the dungeon, wipe to some challenging scenario, one player leaves.
Its basically the same thing as M+ is now, except it doesn't take 30 minutes to get all 5 players into the dungeon.
What's even more ironic is the mages and warlocks who just go full aoe in 5 mans and don't bat an eye lash at doing so.
The game is really played differently now, and that's not a bad thing in my eyes.
But it will be in many others, and it will really bother the people who can't seem to think objectively on what Classic is and will be in 2019.
Best just to put aside any of these ideas and assume its going to be nothing like you remember it.