I see what you mean when comparing something like World Of Avatar to Avengers Campus. However, you bring up the parameter of realistic comparisons and Zootopia land. I believe there is a relevant connection between the two. While neither of us want to see Zootopia here, I think it works as a proof of concept that such detailed and immersive lands are still possible. Zootopia somehow prevailed as a land that is vastly more visually engaging than Avengers Campus, both having a roughly concurrent construction cycles during a challenging time. I take this, and the fact that Disney will want to please James Cameron as positive signs.
Offhandedly, you posited whether film based lands need to be identical to their source movies. I'm not completely sure they have to be, although it's worth remembering all the people who complained that Galaxy's Edge was an invented planet. I don't mind this though, it looks like Star Wars, the fault is that it just seems to feel empty. As far as I can tell World Of Avatar is certainly more pleasing to behold than Galaxy's Edge, but it doesn't look all that much like Pandora to me. The trouble I run into here is that if I'm meant to be stepping into the world of Avatar and it's beautiful, but feels inauthentic, was it really worth devoting a whole land to a single intellectual property? Personally, I'm not so sure it is.