The video is pretty cool, but most of it isn't really news. I saw a montage of the
Robin Hood stuff about two years ago on YouTube. The reuse of animation in that movie is particularly well-known, since the budget for it was so small that they were frequently forced to recycle sequences from previous films. This has never been a secret and in fact if you look at the
IMDb trivia page for
Robin Hood, it's the first thing that's mentioned there.
The
The Jungle Book stuff has been known for a long time as well, but it's the first time that I've seen a montage of the footage. I'm not sure what caused the reuse of animation in that movie though. Money might have played a role, but AFAIK
The Jungle Book didn't have the same budget problems that
Robin Hood had.