i disagree, not because i am a newjeans stan but because y2k has always been around and there are many different forms of it (take newjeans and tripleS for example, same overall concept. but completely different aesthetic wise), just like the retro concept. when i think of the retro concept, i think Wonder Girls, who stuck to it their entire careers and tried out so many different kinds of retro aesthetics. I also think Shinee. Shinee have, until recently, had that retro funky style of music especially Jonghyun. Western artists like Tinashe have kept the Y2K concept for years (i mean YEARS) before it even got extremely popular with gen z. I feel like their concept will age gracefully. Wonder Girls and Shinee are icons with iconic hits are still hold up today. Newjeans' music doesn't have a specific musical time period, only their aesthetic does and that can be reorganized very easily especially with Min Heejin on their team (even tho I do not like her at all, she is very creative. wish she'd use that creativity on concepts for older ppl). The only reason the huge retro wave of 2020 ended so quickly is because it was nothing but a cash grab trying to appeal to the biggest trends at the time, not trying anything different. Not to mention, there will always be a room in kpop for concepts that invoke nostalgia. Newjeans is the perfect blend of modern aesthetic with 2000's sensibility. I feel like unless the next trend the the polar opposite of Y2K (idk something like dull colors, anti technology, and anti youth), it will last for some time. i do think it will be interesting to see what happens in the future tho because we really never know.