Oops, I think I need to update the post to rewrite that part.
So the itch.io page will no longer receive updates until the final version is released. The May build is the last one until the full release. Once the complete version is released on Steam, it will be a priced title. Therefore, the free beta on itch.io will no longer be available after the game is fully released. The "Steam version" will be available for purchase here as well.
And don't worry, I actually planned to give free keys to those who donated. It was meant to be a surprise, lol.