Not a Niji expert but from I can see an absolute twitter random pulled the term out of his ass and made an off-hand remark about it, that's all there is to it.
The only reason it blew up and has twittertrannies screeching about it is because Aia apparently read it and started coping with "p-pls don't forget the younger waves exist too" (bitch, you're one of the biggest reason your wave flopped so hard) which brought out a circlejerk about how the term is so hecking mean or whatever (even though it's not really a term anyone uses). And then Ver, Enna etc. started joining the circlejerk leading to even more exposure.