Millennials survived the original Y2K skinny craze — and now they’re warning Gen Z not to repeat history. Millennial model and content creator Kaila Uli is going viral for calling out TikTok’s troubling obsession with the “Y2K skinny” aesthetic — a look she says glamorizes the brutal body standards that dominated the late ‘90s and early 2000s. “My first thought was, ‘No, we can’t go back here,’” Uli, 33, told Newsweek in a recent interview. …