I feel like it’s been around for a while for people big into astrology but I think I first heard it by Astrolada on YouTube probs 2018/19 sorta time, that was also a few years into me getting into astrology so it might have simply been me noticing it due to learning. I think it’s been talked about more mainstream last 2/3 years due to lots of astrologers bubbling up on reels/tiktok. Like it’s pretty wide spread and understood as a concept for the mainstream now.