Interesting, but a tad bit unfair for them to say that Disney has been "copying it ever since". I can't real blame animators for not 're-doing' work from one movie to the next. While there may be examples of 'copying', it's important to note that it's Disney copying from itself and not someone else. The stories, overall animation, music, etc is all original from film to film and ultimately that's what counts. Also, if you'll notice virtually all of the films they compare are the older ones. You don't see that comparison being made between Lion King and Little Mermaid for example, where computers aid in the production. These films are all hand drawn, so I think we can give the animators some slack for saving a little time here and there.
Just my .01957
Pete