All of this is true for the near term, but as
@Sharon&Susan is pointing out, will that be the case in the far distant future? Disney putting the disclaimer and delisting it for children on Disney+, means that it won't be readily available for children today to watch. That could impact relevancy in the future. In a couple generations, park guests may be largely unaware of who or what a DUMBO is.
Is the Dumbo experience of a flat spinner ride so nostalgic and iconic that it could stay in the park, without the connection to the movie? I'm leaning toward thinking NO at this point.