This is a long lasting campaign. But the problem with it is that it does not accept members below Hero and that scares members from applying. But why is it that it is always open for new applicants, always. I have not seen a time it was CLOSED or CFNP.
Stake management has a unique way for processing application as they'll send you a message informing you if you're accepted or not. If I'm not mistaken, this campaign is somehow exclusive for Hero Members only but it also accepts Full Members and above if you have the previous Avatar set which is animated or if you're a reputable member.
It looks like previously, the campaign almost got Full but some participants was removed or was kicked from the campaign. They also have a large number of participants which is why it never got "CFNP" status.