Hi, the same thing happened to me. After being indexed for two years, my game has suddenly disappeared from search results.
I'd really like to see itch.io adopt a review system similar to Steam's. Games are reviewed before publication, and if there's a problem, the developer is told what needs to be fixed. They can then address the issue and resubmit the game for review. Once everything is approved, the game can be published.
But on itch.io, there's not even a basic notification system to tell developers something like: "Hey, your game is no longer being shown in search results because our system flagged it. Here's why, and here's what you can do to fix it."
Being left in the dark without any explanation makes it incredibly difficult to understand what's wrong or how to fix it.

