I honestly feel like all this streamer gate, long queues, etc stuff is just the result of everybody having to wait around for so long to get in to the game for the first time (again). I think that everybody is overthinking this whole thing. The hype and long wait is causing major theory crafting and mass hysteria.
Will there be long queues on day one? Yes. That was going to happen no matter what for a game doing it's first classic server experience with a fan base of 10 million+.
Will the queues calm down? Yes. Of course they will. Give it a week, and things will be normalized. I personally don't think there will be a mass cancellation of people to cause it, but rather the average player will lower their amount of time in game per day, and that will cause a normalization of login queues.
Will there be toxicity? Yes. It's World of Warcraft. This is to be expected. Ignore it, and move on.
Will there be streamers causing disruptions in the areas of the world they are playing in? Yes. It likely wont effect you in the least. It's not like they can be in all parts of the vast world that makes up WoW at all times. On top of that, a large portion of the time people spend in WoW is in dungeons. WoW dungeons are not public, so guess what. No streamer disruptions for you in those dungeons.
Will there be large private server guilds racing through the content waving their over grown epeens around? Duh. Of course. Does that mean jack shit to you and me? It shouldn't. If it does, then you probably need to rethink your life choices.
TL;DR .... chill out. Everything is going to be fine. See ya on Whitemane.