Twitch viewers call themselves siehkyle and thus provoke a spell?

I was recently followed by a user on Twitch who had the username "siehkyle". I basically read out all of my followers and didn't even notice the user's malicious intent and read out his name, which sounds like a right-wing radical slogan. I immediately apologized, said that I distance myself from something like this, banished the user and deleted the VOD. Do I have to fear a ban because of such a troll?

No you will not. Since you have already deleted the VOD, a ban is excluded if no one shows you at Twitch.