I was thinking about it earlier today, and I can't think of another line that has the company flat-out saying "no specific canon! Do what you want!"
Transformers, GI Joe, TMNT, DC, Marvel... those are all the ones I can think of... all of them have been retconned or reset to explain the difference in character appearances, allegiances, or origins. But for MOTU, mini-comics and Filmation or just as valid as UK and Classics!
I think it's kind of neat that they're not trying to pigeonhole everything (although Classics does pull a little from all, which I'm personally enjoying, but YMMV), and that each story is acknowledged and embraced.
What do you think? Are there other toy lines that have this? Am I the only one that likes this?