Splash Mountain was built on repurposed animatronics, so re-theming is already part of its history. As a ride, I don't really mind this idea -
as long as they use Dr. Facilier to keep the creepy tonal shift right before the drop. How it fits into the theming of surrounding lands has potential issues, though. At
Disneyland, it's right next to New Orleans Square (and Critter Country has pretty much become just "the walkway to Galaxy's Edge"), so you could just annex Splash Mountain into New Orleans Square and the re-theming would still fit. It's a bit more of a problem in WDW, since a New Orleans-themed ride doesn't really fit in Frontierland.
For those who haven't seen PatF, I'd recommend it. The first time I watched, I was a little perplexed since it felt like Disney, but at the same time didn't feel like Disney. Finally I realized that we'd become used to post-Mermaid films as what "Disney" is, but PatF feels more like a classic late 60's / early 70s Disney film like Robin Hood or Jungle Book, so that's why it felt familiar, but still not.