So I time travelled for hours last night, and my most recently moved-in villager, Lolly, refused to have a thought bubble! I met all the requirements as literally every single other villager had a thought bubble at one point, just not Lolly.
Will the most recently moved-in villager refuse to move out until you move someone else out first?
yes, in previous patches it was bugged to where the last moved in villager could ask to move out (and depending on when Lolly moved in this could possibly be the case but I wouldn't count on it) but in theory the last moved in villager shouldn't ask to move out.
Yeah, you're going to have to move someone else out first with the thought bubble method. It is possible if you find a camper during your time traveling, that the camper can request Lolly to move out then, and immediately put her into boxes.
Since you are TTing, note that villagers will not ask to move out on Saturday since KK is there. They also won't move out if there's a special event happening on that day. Your newest villager will also be at the bottom of villagers that will ask to move out.
I just did it last night and found this to be true. I found a guide that suggested to move 1 month and 1 day ahead, save exit, roll back 1 month (so you'll just be 1 day ahead of the real date) and continue to move it up 1 day until you come across a villager asking to move. Mine didn't show up until the 7th day which would be next Monday.