You are not a bad poster tbh but you should not be spreading false informations in the way you have done here. Due to that you are being removed from the campaign.
Sorry bro, nothing wrong with @arimamib post, here he was talking about the total post, and why it can be minus post for users. Its not spreading false informations. He just wants to let other members know, how the total post count end of campaign each weeks, because sometime, member can lose their number of posts. IMO, he still eligible for your campaign, since there is no false informations, i think you have to translate their word better,
But, in the end, you and your team have the right decissions about him, but for us here, his post isn't wrong.