I know the subject-line must be not up to the point. So, let me explain the basis of this topic:

A campaign can have rules on what are the board's/topic's posts are countable for payment and what are not.

But, a rule like if you post on some topics or boards then you will lose your slot, is it right approach?

The better rule should be, not counting those posts.

As per basic rights and freedom of speech, we all should be allowed to write anywhere and a campaign may exclude posts as per their rules from counting toward payment and should not cost the spot if minimum post count is reached after excluding posts which are done on excluded section/board/topics.

I like to listen your views on this.