Your game was published three days ago. There was no time for it to be indexed. Edit: did you delete and recreate the page? In that case it's treated like a new game.
I mean the search pages in itch.io site using tags and filter not Google. I guess that they don't require indexing because they work based on tags and setting information given in uploaded game. My game was shown by them well immeately after I uploaded my game.
My game page was not deleted nor recreated. I just tried to change the settings and information of my game project after I found that it was disappeared from the itch.io search by tag pages.
There is no "required" review process. If you saw your game on internal itch search, it was indexed.
But your game can be put on that review list after publishing for any number of reasons that you usually will not be told. You will not even be told that your game is on that review list, or that it passed inspection.
But there also is a possiblity that the recent changes in the search algorithm made your game visible for a short time, while being actually on that review list. There was something about the new search being asynchronous or something like that.
Either way, you still have to wait.