Sounds like a terrible and unnecessary design choice, IMO. Limited time only + exclusive rewards + EX+ level difficulty = I ain't doin it and most people won't either. If it's just a level 80 slightly enhanced version of the original trial, then that's 50% okay, since arbitrarily limited time content is stupid no matter what it is.

Honestly, I do think the fundamental idea of making max level versions of old content is a cool concept, though. I'd love it if they made a level 80, 8-man version of the old Crystal tower series to allow people to really experience that content in a less faceroll state.