If you go through villagers in your void while not interacting with those that have voided villagers- the villagers lined up to move into your island queue will be empty. Plant a bunch of weeds/ skip a lot of days and the appeal of your island goes down. I think it's about 50 weeds for another day with an empty plot? I could be wrong though on the exact ratio.
If my ratio were correct though, say I have 200 weeds and no villagers lined up for my town from other people. That'd be 4 extra days with an empty plot. I have gone up to 5 days.