True but Disney had a big hand in Tales from Earthsea. But your right, I just am a huge Ghibli fanboy...
I agree with that statement and would add that longevity would also be a key factor. If they're one and done and nobody remembers them then can they be considered "World Class." I think that the entirety of the populace that enjoy's the anime lifestyle and those that its passed on to would have to watch, and talk and remember those titles. Which is kind of why I chose Ghibli as my contrite answer.
While not all of their titles are great, most people have at least seen them and remember them as well as keeping the discussion about them alive. Even the bad ones, so the other point would be that even if their not great or even good, I suppose if people remember them then they can pass the longevity test. However i will digress and say that this would only be true without the branding effect.
Disney is great at branding, so most people remember them only because of the mouse, and the fact they hold the copyright on most integrated social stories.
I agree with this statement as well. Cliche' stories should never be ruled out simply because they are cliched. As you stated with MHA the main character grows and develops thus diverging him away from the generic that his was based on. However will the story itself run and pass the test of longevity?
Anyway, just some thoughts. Truthful, what one person see's as world class doesn't mean others will. This would be a incredibly hard standard to create in order to identify and classify anything in the category.
One other thought I had was that it would have to be accepted world wide in order to be considered world class. It can't hold a that title if the anime itself isn't good enough to be found globally.