I wondered too. Not because of the maintenance specifically, but the update. It's worrying, because it tells something about the dev.team

They did an emergency maintenance to fix a bug in an item than most players don't have, didn't have the time to get, aren't interested to get, or didn't even know of the existence.
And they haven't completely fixed the earring. They just fixed the f******* +10% XP bonus.

What are we, the players, for the devs. Some kind of XP addicts?