Do understand people who buy on itch get the full game on release, that full release will be here.
Sites like patreon and subscribe star get development releases, while people here "stable" releases. That means less frequently but high quality and with new content. Not just a preview or something. Not every update is worth playing, especially if it's content you want
Support on patreon/SS to support development, if you want to buy the game you've already bought it here.