Errata Notice: I made a wrong assumption about the school bus not showing up. It wasn't an erased portal, it was a mod.

I was making experiments and believed that it was visitors staying overnight, but later turned out it was just a coincidence.

I discovered that I made a mistake on my 50/50 checking. I redid it, and found the culprit: Phaenoh_SummerVacationWintersDay from 'Let Kids Be Kids'.

I apologize for the misinformation I spread, and I want to thank r/SuitableDragonfly because he made me rethink my assumption and check the portals.