For now, I would resubmit. The scorers can remove the "oldest" and keep the "newest". Unfortunately, you will have to do all of them, but that should be easy since you can "see" your current picks here.
We could, but not everyone may want that and it would be a ton of work for the scorers. Remember, they have jobs, families, etc It's easier for everyone to just resubmit, than for the scorers to sit and do 90.
Is there an easier way to change your prediction of one skaters placement or you need to submitt the whole list discipline by discipline once again just because of that one change you want to make? I mean, there is nothing more valuable for the predictions game than 'edit post' button