For the record, I'm hopeful for this project and generally think MBO and FEA were well done. You're also totally right that when you go through those rethemes there isn't a trend of getting rid of physical elements for digital ones. That being said, I think some of the concern people are feeling around disney touching this attraction is that they just don't make rides like this anymore.
Splash has 60+ animatronics and most modern attractions don't even get close to that. Rise has ~10, Navi River has ~1, Pirates in Shanghai has ~5, Frozen ever after has ~10. The last ride they did that's as animatronic dense as splash is maybe Sinbad but that's been 20 years. I don't mind this trend of fewer figures that are of higher quality, but that would be represent a bigger change for Splash.
I think that's some of the anxiety people are feeling. Less, OMG SCREEENS, and more that a shift from loads of lower quality figures to fewer key figures of higher quality risks losing some of the charm that made Splash a classic ride.
That being said, I'm optimistic they can reuse some of the old figures and do something great here