How do you know if you have villagers in the void

[Lotusblossom]

I was wondering if there was a certain amount of days that it will take for someone elses void villager to move into a vacant house if they're in your void

 

[FraudulentDimetrodon]

If there's a voided villager in your move-in queue, they will move into an empty plot the following day at 5 a.m. (that's when the day starts in NH). You'll know if they're a pure RNG villager or if they're a voided villager when you talk to them; a voided villager will mention that they moved from another island.