With AI tooling, we are in the era where rapid iteration on product matters more than optimal runtime performance. Given that, implementing your AI tooling in a language that maximizes engineer productivity makes sense, and I believe GC does that.
One would expect that "AI tooling" is there for rapid iteration and one can use it with performant languages. We already had "rapid iteration" with GC languages.
JS/TS has a fundamental advantage, because there is more open source JS/TS than any other language, so LLMs training on JS/TS have more to work with. Combine that with having the largest developer community, which means you have more people using LLMs to write JS/TS than any other language, and people use it more because it works better, then the advantage compounds as you retrain on usage data.