Others can answer, but I believe Tokyo's Splash is very similar (if not essentially a clone of) MK's version, as opposed to DL's version. Thus, it would be easy to port any changes between TDL and MK while more difficult to use much of any work from DL in either.
If this is true, it might be a blessing in diguise for MK guests - assuming that Splash "has to" change and Tokyo forces WDI to develop a theme and attraction to their liking, it might result in whatever that ride being developed ending up better than what WDI will design for DL. Surely, OLC isn't going to just accept a value engineering replacement to that popular gem of a ride.
I know this is the wrong thread to get into details about Splash, but I’ll say the relatively small group of pro-change fans might regret the rush job they initiated within the current state of the WDC. Hope the DL faithful enjoy cutbacks, screens, and the cheap projection-face AAs. This could change, but it’s the direction I’m hearing about right now.
I’ve heard two examples:
(1) Think Epcot’s Frozen, which works on the small scale of Maelstrom but would be conspicuously insufficient within the Splash show building. *shrug*
(2) Look at the gut job on the GMR and the vast spaces of flats and projections in MRR *oh no*