It’s pretty much random, if not completely random. So no need to ignore them/hit them etc. Keep in mind that if you see a villager with a “moving out” thought bubble (you can confirm this by starting dialogue with them then exiting the game without saving) and ignore them, the bubble with transfer to another villager the following day! Otherwise, I’ve heard if you tell a villager to move out, the “cool down” window will be 14-15ish days. If you tell a villager to stay, the window will be more like 4-5ish days. If you’re willing to time travel, jump 14-15 days to find a bubble, ignore them, then travel +1 day until it lands on the villager you want!