It's not even necessarily the most recent move out too. I once picked up someone from my daughter's void that had moved out months prior and she'd had several people move out after.
I get a lot of villagers from my boyfriend's town because we wifi together a lot. He somehow got a few high tier villagers just from starting his village (Julian, Fuschia), so I got Julian without even talking to him.
And yet, I talk to Fuschia in his town and she doesn't come... D':
Because my villagers are constantly changing (I only hold onto a few, otherwise it's too stressful), I get a LOT of voided villagers. I don't mind too much.