Creature boat ride just seems like such a perfect fit, I really hope it happens. "Atmospheric indoor boat ride" is a niche that WDW has filled like five times over; it's about time Universal got one.
I also wonder if they might consider a permanent haunt to zhuzh up DU's offerings without using up a ton of land. If there's lessons learned from the Vegas haunt about how to operate a permanent HHN-style house with minimal staffing, maybe that could transfer over to making a viable permanent walkthrough attraction at DU? Especially since out in Hollywood they seem to be experimenting with "HHN style walkthroughs but less scary" for Fan Fest Nights, so the intensity level could be modulated down from HHN standards to match the rest of the land if that was a concern.