I meant to put this here earlier, but as https://status.atlas-media.co.uk/ has shown for a while now, the retry of the flatlands is scheduled for the 8th of January. As I said above, this was postponed to keep the holiday season free. Like for world "world", a temporary world will be put in place so that there should be no notable downtime.
Also, I haven't forgotten about the lost data, I will take a look at it after this (hopefully last) maintenance.