I delete my prediction post because I think it might make my profile look low-quality poster, in case my signature campaign ends I can apply to other campaign. That way, if I apply to an open signature campaign, I’ll have higher chance of being accepted.
I don't agree that joining prediction contests can reduce your chances of joining a signature campaign, as long as your post history is not filled with
only predictions from contests in the games and round section, then campaign managers would not have any problem with that. These contests are free, and if a regular user takes out a few minutes of their time to join some of them, then that is okay.