I thought there was a 15 day grace period after someone moves in, before someone asks to move out?

[eeveelovee]

So, I just had 3 villagers move onto my island... 3! Coco was first, then Portia last. Then.. 2 days after Portia moves in.. Coco asks me to move out?

I thought there was a 15 day grace period before anyone asks to do this? Or am I wrong?