Some people reported that their accounts magically showed up again undeleted after a week or so. No confirmation, just saw a post some time after the blackout started. So beware to check after some time.
This is the only reason I’ve kept my accounts up. I have a script that undeletes any comments that resurface, and a cron job that runs that script at regular intervals. I don’t know if any comments remain. Reddit says there are none remaining, but I don’t trust them. However, I can’t find any of my comments (same username here as in Reddit) out there through a web search so, I guess it works?