I would be only mildly surprised if some group of channers would plan that. Despite their toxicity, they are the most focused and determined group I have ever seen. So bad it is always for destructive purposes. They could have been great people.
4channers are remarkably resourceful and effective at times, if any group could manage such an ambitious task as poisoning all LLM AIs it would be them. I've heard it described as weaponized autism.