But what about the fresh games?
I don’t know for sure, but if next to “Fresh Games” you click the “View more ->” button, you arrive at this page: https://itch.io/games/newest/fresh
On the top of that page it says:
Browse a constantly updating set of projects sourced from a curated collections by our members. Check back for new additions.
Based on that I assume this also goes through a similar process like the featured games.