I don't know why anyone would want Disney to buy these rights - they can't even begin to properly exploit most of the properties they have in their theme parks. Look at Avengers Campus or Frozen Ever After. If fans want a LotR land (or lands), it has to be Universal.
I don't see here that the specific rights to LotR and Hobbit off-shoots would be non-exclusive, and for a theme park land, those are the relevant IPs. It does highlight the tricky, loophole-laden nature of the rights and the litigious inclinations of other parties, however, which might be a deterrent. It would take a much longer article to sort the whole thing out.
I'd argue LotR absolutely does still hold massive appeal to a wide audience, and along with Star Trek and the DC Universe is one of the last huge IPs without a strong theme park presence. It has an easily identifiable aesthetic, multiple complex, appealing, visually distinct settings, and an absurdly fleshed-out world full of objects and foodstuffs that a theme park could exploit. The original LotR remains, in my opinion, the most consistently artistic successful trilogy in pop culture, with only the first three Toy Stories offering competition (do they still count as a trilogy?)
The idea that LotR is "hard core" or inaccessible is silly, especially in a world with hit media based on Game of Thrones and The Witcher. It's DNA is woven into almost all modern fantasy (in part because of how adroitly Tolkien repurposed existing mythology) in a way akin to how "Disney's version" is woven into modern fairy tales. It's in the pop culture zeitgeist so that even folks who haven't read the books or seen the films know some of the terms and ideas, just like SW and Potter and Trek. And the idea that Black Cauldron or Willow are in any way comparable is madness.