No. This is coming from someone with ADHD and anxiety and a myriad of sleep disorders. At least, "disney adult." The other two maybe, since it's also used by reactionary sources. But regarding disney adults, it's usually referring to bougie adults whose entire lives revolve around loyalty to disney products. I've never seen "nintendo adult" before, but if it's the same thing it's no different than "sony ponies" or "xbots" or "nintendrones". Just blind loyalty and obsession over a product to the point of anger if criticized because they've made it their identity.
In my experience, disney adults are always richer than the average person. I mean, that makes sense, why else would they be able to go to disneyworld every week and make their whole lives disney? Game fanboys tend to be more diverse since games are relatively cheap compared to planet tickets, hotel fees, and disney tickets
Doing childish things is fine. I have plenty of stuff animals. I even share pics of them with some people. But if you'd be uncomfortable walking into a house where every inch is covered with funko pops, then you'd probably be uncomfortable with someone who can't shut the fuck up about disney and toys after they stop being 13