The campaign is closed for new participants, atleast for now, you can see op announcing it few posts up.
Only 4 people are accepted out of 32 participants who has followers bellow 1500.what special with those 4 accounts?why you can't simply remove them and only start accepting over 1.5k from now?
I suppose that campaign manager took into account the quality of followers, are they crypto related or something else. There are many reasons who is eligible
I'm guessing it's easier to have effect with less participants who have more followers, than to monitor more users who each have lower number of followers. It's what i would do aswell.