@stepan
Nah. This is just a method, that is used to subscribe from different server, then the one with your account.
If you open the account you want to subscribe to THROUGH the server you are using, it won't need to find out, what your original account is.
@LukeAlmighty yep. As I a have my own instance and as Mastodon is not backfilling posts I usually have to look to the user's instance to decide whether I want to subscribe or not. I am used to subscribe when I am there.