The initial article was talking about Grok AI implementing a "typical" anime model, which fits the bill for appearing young, it specifically mimics the look of 17-19 year old Misa. 13 is absolutely a stretch here, but there is a valid question to consider.
When there's a well-documented problem in the real world of young girls being seen and treated as more mature than boys of their same age, we should give some thought to why that might be, if only to try and make increasingly less exploitative content in the future.
I see. Yeah, it didn't really come across as "anime (style) as a gateway for creeps" due to the initial phrasing. In that case I'm fully in agreement. Though I'd like to add that the AI companion thing itself is a worrying trend considering AI psychosis.