If I vote to reject an unpublished review, I typically write a few comments about why I rejected the review. If the review has potential, I'll offer a few suggestions about how to improve the review along with encouragement to resubmit an improve review.
I suspect (hope) that these comments go back to the OP. I don't know if the reviewers names are included in the rejection notice? Perhaps not, as I've never received any PMs complaining that I rejected an unpublished review.
I wonder how many writers of rejected reviews use the suggestions to improve their review and resubmit it and get it published?


It's impossible to know if a person rewrites a review and re submits it because the are no names attached to an unpublished review. Not sure about the rest of it.