With the passage of Amendment 4 - Voting Rights Restoration from 2018, there's been a continuous back-and-forth between the state and former convicts, as they attempt to use their newly constitutional right to register.
So it could be them trying to purge the rolls of anyone they've flagged as a felon voter that the state refuses to acknowledge as re-enfranchised. There's also been a number of efforts to reform election law and tighten who can vote. So they maybe purging old mail-in ballot voters under the S.B. 90 bill.