I will point out again that people have been complaining about classics being removed, and nostalgia being lost for 30 to 40 years now, and the places has still performed exceptionally well and gained even more fans and follows in that time.
This may be hard to hear or understand, but there is a huge gap in the concept of what Disneyland is between the fan community and between the broader group of people who like going to Disneyland but don't usually think about it all that much. The fan community will always weigh the value of the experience in the minute details of the tangible experience: how many rides a park has, how many animatronics a show has, which imagineer worked on which ride and which ones are connected to Walt. But the broader audience, the one that Disneyland was really built for, doesn't care about any of that at all. They go because they want to spend time with their family. They go because their kids like meeting the characters and they can post the pictures on Facebook. They go because the rides are fun to go on. Because the rides are thrilling or have cool effects or some character the kids like.
In short: they do not think about things in any detail and as soon as they leave, they are done thinking about Disneyland for another year.
I think we all generally understand that, as long as the Frog ride is good, people will ride it and not care that Splash was removed. As long as the ride is still evoking the same feelings as the original (being fun, thrilling, innovative, etc), people can still feel nostalgic when riding it, because it's the feelings it evokes that they are pining for, not the specific animatronics, the paint, or the art direction. And to expand that to the broader concept: as long as the core reason people visit Disneyland remains the same (the nostalgia for being with your family and friends) then it doesn't really matter which attractions they end up removing or replacing.