In general you are absolutely correct that ANN thread is to discuss anything related to the business, there is also no specific rule that we are not allowed to talk about it but it is just rare to see ANN thread is being used to discuss about the payrate of the signature campaign too much/further. At least I do not see people talk about the payrate of the signature campaign in other ANN threads. In my point view, ANN thread is better to be used to discuss more about internal things that we can find on the casino's site, such as promotion, games, deposit/withdrawal etc.
So what if certain discussion is or isn't rare? People tend to talk about what's interesting to them at the moment, that's what natural conversations look like. And right now, the return of LL and the signature campaign are the most interesting topic. If anyone has something more interesting to say - feel free.
As with any other type of discussion, it will die its natural death, so need to panic.
Actually there's no rules set regarding on what topic a user should discuss on the ann thread and I think what currently happening to them is relevant to the discussion and since lightlord's comeback is good news to other people especially he brought up his signature again then expect that this will be a hot topic on their thread since there's no other thread created for this discussion so users could go there. I think even if discussion of that matters happen I guess casino owners still like that since they want their thread to bump up by those discussion since it adds exposure to them. For soon those discussion will fade out and people will talk about those gambling activities they experience so we don't need to get anxious on situation which is currently happening here since its pretty normal.