I believe it is best to never reference this place. But they definitely at least know we exists.
There is this thing called youtube analytics where they show exactly how people found your youtube videos.
For most EN vtubers it will look like this:
youtube/google 50%- reddit 24%- discord 20% - facebook - 4% - TVA 1% - random ass forum/website like spacebattle 0.001%
Judging by how insecure and noombers obsessed most vtubers are. There is no way bigger ones like phase hasn't browsed this place. Ego search is popular even in JP. Even nijisanjiEN was caught browsing /vt/ before they lost relevancy.
However, at most once in a blue moon, they wont be viewing this site everyday.
Tl;dr your oshi knows when you are a cheating