As you may know, the explore page has measures in place to prevent people from staying on the explore page forever and to keep projects fresh.
What I and others have seen is people working around the system to get their projects continual access to the explore page.
This is achieved by unsharing and then sharing a project again to trick scratch into thinking it's brand new.
I think more measures should be put in place to:
#1 make abuse of the system a reportable offense
#2 add some kind of algorithm to detect based on the project first being shared and not when it was most recently shared.
I would see no downsides to implementing something like this as it would not be noticed in regular use and it just prevents abuse.