I mean, we've been here before with guldan.
There will be a raid where we fight sylvanas and defeat her, then onto the next big bad being death or whatever they're calling it which will eventually end up being linked to the only remaining big bad after that, the void lords.
And that's basically what the expansion after shadow lands will be like. Except it will be a shitty filler expansion that's mostly used as a build up for the next good expansion and so on.
Do people seriously still fall for blizzard's bullshit repackaged fresh coat of paint every year?