Yes. I understand this. And the show COULD have explained it any other way, too. The things you know and the things the show tells you aren't god given facts. The writers wrote it. And when the writers want to write something else, even something that seems REALLY absurd - for example a story about a time-traveling Loki fighting against another female Loki and then taking on the Lord of all time, even after Loki most definitely died - then they find a way to do exactly that.
Loki and Sylvie sitting in front of that desk, listening to a dude explaining the Lore for 30 minutes wasn't the inevitable consequence of what was happened before. ANYTHING else could have also happened, if the writers wanted it to. And I would have preferred most other ways to a stale wikipedia lore entry. That's all I'm saying.
But this is how it always works. The literal progenitor of the "man behind the curtain" mystery is The Wizard of Oz and Oz himself spends time telling Dorothy and her friends that they never needed to seek him out because the things they hoped he would give them, they already possessed.
Kang was the man behind the curtain and, amusingly enough, he wanted Loki and Sylvie to do what we expected they would do - I believed Loki would take over the TVA but make it more transparent and less destructive while Sylvie joined the mainline MCU to help them fight off a younger Kang, but the show itself went with something much cooler.
Now while it's entirely possible Sylvie will still do something like that since she now has a device that grants her unfettered access to the multiverse and all the knowledge she'd need about the previous Multi-Kang war, we have no idea what's going on with Loki. He's back at the TVA, sure, but is it the same one? Does every universe now have its own TVA and he's in a different one, or has another Kang already taken over the only TVA that exists?