As mentioned previously, the show in Tokyo acts as their fireworks show (though with 2 nightly performances), so I would expect to see a reduction in pyro for WDW. TDL has historically had trouble doing large fireworks shows on a consistent basis due to the winds off of Tokyo Bay, so the reliability of OUAT and its low-level pyro has been well received
From what I remember, it's a very good show, but not a great show. It uses the projections well and has pretty good pacing, but relies a little too heavily on the architectural mapping gimmicks and has some dull parts. IMO, Dreams at DLP is still the best projection/multimedia show, but this one isn't bad by any means. It will be interesting to see how this is received in WDW, where projection shows have always been supporting players to the main fireworks, since this was created as a featured show.
Although this announcement came as a surprise, I'm still somewhat disappointed that they decided to replace the relatively-new projection show, rather than the highly overrated fireworks show that should have been replaced years ago