Not a bad idea but it wouldn’t solve the problem, as the original flags still aren’t resolved? So reopening would be premature.
The more I think about this, the more I realize there’s no good solution to this problem. The topic has to stay closed until the flags are resolved somehow, thus the only action that makes sense is for the system user to only post when the topic can be properly opened (because the flags were resolved), and announce the reopen. We will improve the copy to indicate this is the case:
This topic is temporarily closed for 4 hours due to a large number of community flags.
Discourse auto-ignores all flags older than 90 days as a sanity check, because if flags haven’t been resolved in that long, they’re never gonna be. But that’s irrelevant on a site like BBS where all topics close in 5 days anyways.