Like the title says.
So I travel to Solstheim and immediately get involved in some quests. I barely make it out the gates of Raven Rock and I'm already loaded down with stuff. Since the Smith is asleep, I figured I'd get a room. After the sleep timer runs down, I get a loading screen followed by "Discovered: Temple of Miraak." There's Frea, shouting at everybody (and I'm still loaded down with swag).
It seemed kind of like a weird and awkward transition, with no in-game explanation, so I loaded an earlier save. This time I slept in the abandoned house (using a bedroll from Dovahkin Relax Mod).
Teleported to the Temple again.
WTF? Is this supposed to happen?

Yes. Its supposed to happen.

Did you talk to frea after you snap yourself out of Miraak's control? She explains everything...

You're being controlled by Miraak.

All right. I guess that makes sense,
I was attacked by a cultist almost immediately (though I wasn't moving until I got hit), so I must have missed that I was being controlled as well as her folks.
Thanks, all.

I love that this happens. I adore it. The first time I experienced this is when I slept in Severin Manor. On my way back to Raven Rock I saw a trail of townsfolk walking to the shrine, all of them under his control. They snapped out of it mid-way so I assume time ran out.