I've been running with some other players 3 out of 4 of the defera invasion hard missions. Omega mark rewards have been added. We've played that out of the fleetmark event so I won't be able to make any report on it.
Everyhting worked as usual, even the ultra bugged city hard which still needs a lot of time to completely reset (if you play a city hard room it'll take sometimes more than 1h for that room to be ready to be played again without using the glitch consisting in waiting in that room till the 3rd part of the mission starts, and it's worse if a close room has been played recently).
Several positive elements: the reward boxes and the craft are still there! Defera will remain a great place to stuff our new VA characters.
I don't know if it's working as intended but we had a lvl 26 player in our team, he didn't get any omega mark reward. 10 fleetmarks only for him. It might be "working as intended" but giving sub-50s chars the marks wouldn't hurt the game since they wouldn't be able to use them in the rep system, if it's opening at level 50.