Doesn't bother me. If it did, I'd block them. I actually found the whole thing a rather entertaining spectacle of flavor. I'm a middle age cis white guy. If you want to be called tuba, or tata, or whatever, I don't care. If you use a foreign language like Chinese or Arabic I dislike my own ignorance and inability to understand, but I still respect the person's decision.
Ultimately language rules are only a loose correlation based on use and culture. Rules and norms do not create language or cultures, people do. I only see people resisting the patently unfamiliar. "Dragonfucker" or any other pronoun is no different to me than a nickname. If something so simple is able to make just one person feel a little better about their life for a few moments, I'm happy to oblige. The Hippocratic aphorism "first do no harm" does not appear violated in my opinion. If annoyed, block them.