I had masterworked my Tibaults pants up to level 4 a week or so ago, but then reset them yesterday, right before or after the World Boss at 12pm EST (which spent the 5m gold). I confirmed the reset worked because I compared it to some other Tibs I had sitting around and confirmed that the ranges reset.
When I logged in last night after patching, I noticed my Tib was undone to Masterwork level 4. Im not sure if my 5m gold was given back to me, I didn’t keep track of where my gold was before. I’m happy to provide screenshots of the item in its current state, if that helps.