Sounds like a missed opportunity. Why not have a land like that, with a Cars ride or two? I don't think the Cars IP will still be popular 25 years from now, so I do think the land currently runs a huge risk of becoming outdated relatively quickly.
The same goes for Guardians of the Galaxy. The comic books weren't that popular for the general population, and is anyone gonna be watching the movie 30 years from now? I think part of what makes Disney parks special is their ability to create attractions that last through generations- that kids can grow up riding, then share with their kids. DCA is lacking of anything like that (with the possible exception of GRR). I fear in 10 years, people will have moved on from Guardians and the attraction will lose popularity.