Early Access is not a way to crowdfund development of your product.

Early Access is not a pre-purchase

Do not make specific promises about future events.

However, they have added this which makes my original comment null

Don’t launch in Early Access if you are finished with development. If you have all your gameplay defined already and are just looking for final bug testing, then Early Access isn’t right for you. You’ll probably want to send out some keys to fans or do more internal playtesting instead. Early Access is intended as a place where customers can impact the final game.