I mean fundamentally outside of Mario, Zelda and Pokemon this is true for just about any other nintendo franchises they can draw from after those, young or old. They certainly aren't making a whole land (or probably even rides) out of metroid, fire emblem or kirby (and how well known or popular any of those are outside of gaming circles is vastly overestimated), and stuff notable like Donkey Kong and Yoshi are already coming under the "Mario" umbrella (Same would go if they consider a Luigi's Mansion down the line). But Idk, again they have put bets on things far less popular, certainly not classic/known by all ages, and potentially much more "flash in the pan", idk how many know what How To Train Your Dragon is or will circa 2025~ and by the time they are considering putting anything in the parks those "Younger People" will likely be in their Early to Late 30s if not 40s anyways. And don't get me wrong if I had a choice of nintendo ip to make a land out of after Pokemon and Zelda, it would be Splatoon, but that's also "too young", "mostly popular in japan" and whatever else.