This is probably individual and mileage varies by platform, planet alignment and what not, but I never noticed anything like this when playing the demo. Doesn't mean there wasn't any pop-in of course – well, certainly none as egregious as the linked video at least, pretty sure I would've noticed that – but I don't recall any whatsoever, either in the action sequence or subsequent city exploration.

It might’ve been because your attention were fully utilized.

Like in that video where you had to count how many times people passed the ball, but failed to notice a gorilla walked through the scene.