Thanks for pointing that out! I remembered there being a category for games in development, but I thought it was a general list for anything uploaded, not something tied to the actual search filters. I missed the other statuses when I was looking.
That's the one issue I was considering, having to rely on the developers to update the status. I do see many that update their game page to mention it, but some kind of integration with the reporting system would probably be best to keep it vetted by the community.
It would also be nice if the release status were displayed directly in the search results rather than on mouseover, but in a way that isn't intrusive, like in small font next to the genre or platform icons. I don't know how feasible that would be, though, or how many people would want that. Either way, thanks!