That doesn’t limit formation of a subcommittee to concentrate their discussion for the health of the group. Any topic is eligible based on group impact regardless of its perceived breadth by those avidly discussing it.
Subcommittees/subgroups are perfectly fine of course. But, again, given the context, this isn't that case. This is a core person in the ecosystem making a strong suggestion about how general groups should operate. Doesn't take much imagination to see things get to a point where only groups that seriously discourage or outright ban anything re LLMs are considered "legitimate". It's their prerogative of course but... lol.