I feel like this is how they’ve done every expansion the last few years honestly.
Since WoD it’s felt like the only role of any given expansion is to set up for the next one, like Blizzard cares more about foreshadowing than about telling the story presently going on. WoD cared more about setting up Legion than about fighting the Iron Horde. Legion cared more about constantly, obnoxiously going “Ooohhh get ready for Old Gods next time I bet you won’t expect Old Gods!!!” than about fighting the Burning Legion. And BfA cared more about prepping Sylvanas for Shadowlands and vaguely hinting at the Jailer than about fighting N’Zoth or the faction war.
And so following this pattern, I fully expect Shadowlands to care more about foreshadowing the next expansion than about fighting the Jailer.