It’s half baked: like the post says, it’s the first testing version. It will be developed more, like a member of the team said:
Our plan is definitely for it to become an official variant of Manjaro. With the community testing version we’re now gathering some feedback on what people expect from such a variant and what should still go in there or what could be slimmed down.
It’s clearly not ready.
I don’t know for the AUR, but the regular repos seem to be already accessible. You can try them with pacman, but the installed packages will be deleted at the moment of the update, or you can create a custom image and add the wanted packages which will be reinstalled at every update.