There was a problem on the database and we had to restore a backup, I managed to restore most data, just not a couple recent threads.

I don't get it. When a older backup was restored the thread would be still there.
I would have expected an announcement in the forum about this since private messages could been lost too? And you want to know how old the backup was to recreate communication where possible.

Private message were not lost - the forum message table got corrupted, a handful of threads were corruped. That mentioned topic seems to be the only thread people cared about. Restoring an old backup would have lost much more newer communication, instead the existing table was fixed.