I have a technique I've used for a couple years and it always works ^^
first, check on your activity log what was the last date you played;
when starting the game, ask Isabelle to change the date and play on that last day;
when in town, talk to your villagers, and either 1) they'll tell you someone wants to move or someone will say they're moving, 2) if no one is moving, the villagers will be talking about gossips or rumors (in a general sense, not like "I heard (villager) is moving", they'll say something like "have you ever been a victim of a rumor" or such). Say no to someone who asks to move or wait until they talk about rumors, and that will tell you're free to move ahead;