Two things:
Hollywood's Forbidden Journey has been running with Gate A (our equivalent of Express) without much issue thus far. The merge happens post locker queue, for better or worse. We thus have no castle tour, but an unexpected benefit is the line inside the castle moves noticeably slower. This allows you to hear everything the characters have to say in each room.
The Dementors hands weren't the issue, approval-wise: a glitch during programming knocked them off a rogue Dementor (contact with an RV), prompting them to remove the others. Either it was deemed a safety concern at the time and isn't now, or they didn't want to/couldn't afford constructing new hands. The issue has always been thew "wall" of dementors before and after the "kiss."