What I will say is on the rejection of post due to previous contributions
some post are rejected due to similar contribution made, but most times when we check the previous contribution made, we see low upvote with reason of the contribution was not explained in details.
We should be able to allow updates to previous contributions made which are not clear for users who will need it, a specific aspect of this is tutorials. Some tutorials which were accepted before utopian updated rules can be updated with new detailed tutorials that will help any user that needs tutorial on that specific project.