Before some changes were made last year, a match that received no ratings received an automatic "It's Good", or four-point grade. With the changes in place, an ungraded match will get a 0.0 and won't affect your F.P.A. This way is actually more fair, IMO, as some members may have received undeserved high grades from ungraded matches in the past, and in fact, some were even actively taking advantage of that fact just to reach grading or even Top Match Creator status.
If you want to see more about these grading changes, check here:
As for reposting matches, at this point, I'd say "Why not?" It may be the last chance for them to get graded.