I admittedly didn't pay much attention to the rest of the guide. I was mostly just replying to the assertion that a villager will only ask to move out when your island is at max capacity. That is 100% false. I know that from experience since I was stuck at 6 villagers for weeks while waiting for all the villager bugs to get sorted out, and I had move out requests during that time.
All I know is that the info in the guide is directly from the datamines. I know that they were done a while ago, and not everything was 100% ironed out, so it's possible that there's other stuff at play/stuff that wasn't interpreted correctly/stuff that occurs because of bugs/etc. Maybe the campsite doesn't reset the counter and only natural move-outs do?