They know. The PKGBUILD they provided is exactly the kind of thing that’s in the AUR. The dev’s PKGBUILD wasn’t in the AUR because they didn’t want it to be — instead hoping arch users would go to the repository and use their maintained one. Arch users continued to try to use AUR instead, leading to the dev’s frustration.

I don’t expect this will help anything. If the AUR maintainer is active, they will probably just patch that restriction out.