Aside from the interview, the government already has all the background check data in their databases already. It’s not like you’re applying for a security clearance where agents go around your friends, family and neighbors digging up undocumented dirt.
Do you know for a fact that your background screening does not now or will not ever include calling out to a social media extremist detection service? I'm not so confident.
I’m also not confident in that. But again, if someone has put me in an “extremist detection” database I’m already in the database and the government could already query it.