>Should it be stated that New Year, Stream and Poll threads are the obvious exceptions?
Obvious exceptions are obvious, there is no need to bloat the rules with them. The point of that rule should be clear enough, and it's not to cause us inconvenience nor stick to using a single thread for a given topic (which it tries to prevent in the first place)

>Regarding boards that are meant for dumping 2D images, can reference-only use (single and appropriate) of 3D/reality pics be made an exception?
it's questionable for the lolikon board
i think uploading somewhere else (like Uploader@Heyuri) and linking makes better sense

>Can the OP himself break this rule?
yes, unless they explicitly stated something like "AI OK!" in the opening post or simply started the thread with an AI picture, they can't post AI content even if it's in their own threads