This is an odd one but last night I noticed in my savedinstances addon tab that the 3 pandaria world bosses I normally do weekly were not there. I could have sworn I had done them earlier in the week but no problem I ran all 3 again last night and got rewards so I thought I was wrong.
Today I login again and the same 3 world bosses were not on my savedinstances tab again. I just did oondasta again now for the third time and got a drop and now the boss shows up in the addon as complete for the week.
I will definately check this again tomorrow but it kind of looks like they are operating on a daily timer now? Was this intended?
(of note, Rukhmar from WOD expansion world boss has not reset daily like these – maybe something in remix changed how they work in retail)