I wonder if it has anything to do with furAffinity's inability to operate a site without frequently going to a read-only database.

I mean, seriously, who writes a piece of software that requires periodic database maintenance that can't occur during off-peak hours?

Okay, to be fair, this time they're actually migrating database servers. That's a SLIGHTLY better excuse, but haven't they heard of, say, maintaining a transaction journal and replaying it on both ends? For example? Or maybe using a clustered, replicated storage service that isn't monolithic in the first place? MongoDB certainly has its problems especially when it comes to transactional logic, but what about fA needs transactions to work right? Every single operation on it should be an atomic read or write in the first place.