I don't think it's about anonymous chats, though (AFAIK they're were made illegal in China for some time, just like anonymous commenting). Probably about chats where users know each other. And it doesn't work if there's a snitch among the peers.

For the smaller casual "circle of acquaintances (relatives, friends, coworkers, gaming teammates, etc)" chats, there should be no owner, though - small non-public invite-only communities work perfectly well without administration. This doesn't solve "poster is responsible" but it solves "owner is responsible".

For larger or open chats - yes, the owner should be someone pseudonymous (or just a robot).