It seems Disney doesn't take YouTube clips down. Over the years there's been many Muppet clips online, as well as other Disney properties. I've seen many Disney shorts, specials, trailers, and TV shows online, and I think many Disney-owned movies are on YouTube as well.
The only Disney-owned stuff I know of that's been removed is stuff that was licensed to other companies, mainly audio tracks licensed to Warner Music Group (I find it odd that Disney licensed some theme songs to a Warner-owned label... Didn't Disney have it's own record label back then?).