It's been almost 40 years with barely any new additions to the park and still the 1% complain about any changes like a monument has been destroyed. Please get over it. They are not going to remove Frozen or Nemo or Remy or Guardians, and more attractions like them are coming.
Why? Because it's what the people want. Disney is a place designed for families, and a lot of kids got bored in the park and parents spent the day pushing their children through it rather than enjoying themselves. Kid-cot was a lifesaver, it gave the kids a reason to move forward to the next pavilion. Adding IP sells merchandise, but also creates a pull through the park and a desire to go there.
Personally I think the alcohol sales are the reason the park has been so stagnant. They make so much money off the sales that they don't need to do anything but run festivals. I believe if the park never served alcohol we would have had ten more attractions by now. It's a cheaper fix than any amount of creativity they could nickel and dime out of Imagineering, and they will never give up that profit for anything.
Using established IP is cheap creativity, but that doesn't mean the Imagineer's are not creative. Frozen and Remy are fun rides for the family. You can still marvel at the world showcase pavilions and use the IP to spark interest in the countries showcasing them. France will still have stores, drinks, and food and a movie about France and if the visitor loves the attraction that love will spill over to the rest of the pavilion.
I have no problem with Disney using IP as long as it adds to the experience. I do wish they could have kept World in Motion and Horizons, but I'm over it. Time to enjoy the new stuff