One, the fact that they’re growing (objectively true!) does not mean they are big enough to justify a semipermanent or permanent feature in American parks beyond what is already present.
Two, and I’m speaking as someone who works in the industry, the trades work with entertainment companies to build narratives all the time. You’re not going to get completely unfiltered, objective reporting from Hollywood Reporter, Variety, or Deadline.
Even in that regard as someone who also worked in entertainment (Korean not western) isn't it better to get ahead of trends so you can capitalize on their growing popularity later rather than regretting not have it. I mean there is actual a classic example in Island of Adventure....when Marvel Superhero Island came out Marvel was a box office flop outside of Spiderman which came out after the land opened. DC was what was really really really hot which Marvel was still niche. Then look where it is now and look how ahead Universal was.
Objective truth is animation is trending upwards in general, objective truth number two is japanese based animation is on the forefront of that, it makes way more business sense to me to get ahead of trends rather than wait then something blow up.