@Red225 A lot of people pretty much know who's behind all the avatars one way or another. It's generally common courtesy not to spread that information, but people are curious. If stuff like the Youtube algorithm doesn't just recommend you their old content due to the similarities, you can pretty easily find even entire websites dedicated to collecting this information because there is a demand for it even if it's sort of taboo in the fandom. I'm personally aware of the entire Hololive EN group, and like... five of the JP members?
Some of them are more or less just open secrets, like Gura. Pretty sure most people made that connection pretty quick and the ol' "Don't talk about Fight Club" unwritten rule thing wasn't as deeply rooted in the English community, so... you might even see people talk about hers on her video comment sections. Then other people yell at them for it, and that just gives those comments more views, likes, and replies to rise toward the top. People that want the topic to be treated more like it was for JP side just end up fueling the fire, 'cause people are dumb like that. Look at shit like Twitter trying to cancel various anime for controversies. "Bad" press is still press. Curiosity ensues.