It’s nothing new to report that Disney animators (and animators in general) reuse pieces of animation in their various works. Heck, computer programmers do the same thing by reusing code libraries so they don’t have to build the same thing from scratch every time.
Have you even looked at a Garfield or Cathy panel lately? Ack! It’s almost the same thing every day.
Note that this is a different issue from the common “Disney stole my work” lawsuits that crop up every so often.
To go along with the link at the beginning of this post, which takes still frames from various films and juxtaposes them for impact, here’s a video of various clips that does the same thing. Enjoy.