Also if you want to make an 'Update' for your game even though the jam has ended, there is nothing stopping you from doing so! I would only ask that you keep the original game jam submission version available on the itch page, and make sure that this version is clearly marked as the original jam version of the game. Itch allows you to have multiple builds of your game available, so you should be able to upload game updates as separate builds to the original version.