In the Q&A afterwards, Cameron didn’t announce any disc or streaming release dates but did say he has completed all his work on the 4K UHD Blu-ray, which is indeed real and should be out relatively soon:

“I’ve completed the transfer, all the mastering is done, I think it drops pretty soon like… in a couple of months or something like that. So it’s out of my hands at this point.There’s a lot of added material that they’re sticking in there, and will be available on streaming simultaneously. But I didn’t just want to look at the old HD transfer. I wanted to do it right.”