JP artists will almost always do this whenever they post R18 art of chuubas too. From what I've heard though, it doesn't work that well because of twitter algorithm nonsense. Seems like the main way to guarantee that a vtuber doesn't see a post is to block them.or removing vowels (example: Hana Macchia > hnmch, Momozusu Nene > mmzs nn, etc) in order to lessen the possibility of someone to discover the post you make. This is mostly related to rrat-posting or posts involving dramas that they don't want the talent being talked about to see and probably ruin their day or whatever.