The hiatus rule would officially take effect in January since what we are doing of December's AC has already gone up, but after that, no, there would be no trouble for anyone wishing to reapply their swept characters. There's still a one month waiting period for dropped or swept characters, and people could still be swept for not replying to AC at all only while not being on hiatus ... but being swept for not checking in while on hiatus will be a thing of the past come 2020.