There are many ways you can be revealed as a Bitcoin user. If you don't use ToR or similar software, your ISP knows that you visit Bitcoin resources like this forum. People leave many breadcrumbs that can reveal them even without any chain analysis, they discuss Bitcoin openly on social media or even in private messages (sites like Facebook definitely read them), same goes for real life - one can mention Bitcoin a few times with friends and suddenly everyone knows that they are a Bitcoin user.
But of youre not often doing that,or i mean don't usually use social media to discuss bitcoin then its impossible for them to track that were a bitcoin owner
Like me i am not using my social media account about cryptocurrency..i don't even participate social media campaigns so I believe theres no reason for me to be known as bitcoin user