Normally, yes. However, the Lemmy devs thrust themselves into the spotlight with their words and actions (dessalines themselves has posted Tankie content, just recently a meme about the DPRK dictatorship being “western propaganda”) through their instance

If they just had alts on grad or hex that no one knew was them, or hell ran grad or hex with said, we wouldn’t be here on this comm today.

Instances would just defederate them and move on, but they don’t want that because it reduces their audience.