Hm. That's not a bad idea. But do you want a date of the game's release on the whole internet, or its release on AG itself. Sometimes the games don't come to AG first.
First question that comes to mind: is this for a single game, a gaming genre or all games in general? Because it's easy for ArmorGames to do that for their own developed games which they already do in the ArmorBlog... maybe they wille expand this to other developer's games with AGv3? Who knows...