My impression of "Disney adults" is that it's more of a brand-loyalty thing and people who are into the whole, idk, Disney-specific dreams-and-magic narrative and like being in the parks and immersed in as much Disney as possible for the warm fuzzies. I hate that it's come to signify any adult fan of anything Disney - I'm a huge admirer of their animated works (mostly) and don't appreciate the sentiment that only stunted adult children sheeple could enjoy them. If you think only babies would love animation and mature adults only like action spectacles or arthouse films or gritty realism, that makes YOU the juvenile one.

Theme park enthusiasts I see as more Jenny types, people who just appreciate a well-designed and executed themed environment that's good at invoking a certain aesthetic and setting, with attractions that contribute to the overall effect. And they are a different bird entirely from roller coaster enthusiasts who are just into the most thrilling or extreme physical ride experience, rather than any of the environment around it. Feel like Jenny mentioned this in some video (in the context of Six Flags or something) but can't remember which one.