That explains the patrons and public, but doesn't quite explain where the donators fall into that and what versions that they get. From the explanation you copied, it seem they are getting the same builds as the ones who did not pay. We really need the developers to clarify this.
You're not a donor, patrons are the donators. "Experimental" and "Rough" builds are for them. Itch.io users are considered public since we bought the game. So we only get "Release" builds. Technically the new update was gonna go straight to Release but there were a few major bugs needed fixing first.
From what the developer said on discord the release build was coming straight to itch.io with no month delay. From what I can tell I'm not sure if there ever was one and that wording is really outdated.