Right, so a lot of the young girls singing along with every song will have aged out by the time the sequel arrives.
Same thing happened with Frozen 2.
It's fine for us older fans though — we aren't going anywhere. I've seen the movie 4 or 5 times now — twice in the theater, once with my wife (first time), another time with family... and I've watched enough clips or caught my young nieces watching it that I might as well claim a fifth viewing. I have it on my phone, and putting it on for a few minutes while waiting for something is a good way to pass the time — better than playing an ad-ridden mobile game, anyway.
Anyway, it's funny because in the first movie, they really didn't do shit. Minor spoilers here: they mention a few times they're going to strengthen the honmoon — that ripply layer that keeps the demons at bay — but one time, they mention how Golden is supposed to be the song that turns the honmoon gold, which permanently keeps the demons at bay. That doesn't happen, but when they have their big moment at the end... the honmoon still hasn't turned gold. So they're basically back where they were when the title card slapped us at the end of How it's Done. It's strong but it won't last. Slightly bigger spoiler: the patterns are still there at the end. Being vague to avoid specific spoilers, but just pointing out, they failed in that endeavour as well. Hell, this shouldn't even be considered a spoiler as it's shown on the deluxe edition of the soundtrack, which effectively shows the end of the film. So... all they really accomplished was getting your kids to sing along with their songs. And that's fine — it's still a solid film at least, and arguably a very good one — but the only real thing they accomplished was they killed a few demons, but there seem to be no shortage of them.
Looking forward to seeing how they top this. I feel like they played all their cards but the movie should have had a definite end.