Well it's a hard thing to really say because I think it can be ok as long as the change is blended well enough like say floating leota.
BUT and this is a big but there have been bad ideas too and they stick around for a while. Those pirates are still and may forever chase food.
The big fear for me is if they do something terrible like replace a beloved pirate to add johnny depp. I would be horrified if suddenly he takes the wench selling job away from the guy who is the best at it.
I say changing rides to make them fresh is not a bad thing. Jungle cruise looks cool, and what if they decide to never fix DCA because it's original the horror.