I really enjoy Scalzi’s books, and to the point: it is nice of him to try to take the heat off of a young content creator who has helped promote his works.
The comment is factual, right? The person is young? Check. She is a content creator? Check. She promoted his books? Check. Nothing patronizing about that Edit: meant as a response to sibling comment
In this case "Young content creator" can have the implication that she is not a real success but is only impressive because of her age. Since if she was on the level of a real media personality there would be no need to add the "young" adjective. She would just be a "content creator"
Similarly, content creator can have the implication you run a blog or get your fame solely from social media instead of being good enough for more traditional venues (which could be true, i dont know this person).
Is all that massively over thinking this? Probably. But i understand how the phrase could be seen as patronizing even if literally accurate.