To be fair, I don't think anyone believes that this is the one and only source of the law in all forms. As in if GitHub suddenly started changing it on their ow

To be fair, I don't think anyone believes that this is the one and only source of the law in all forms. As in if GitHub suddenly started changing it on their own, we wouldn't all throw up our arms and resign to our new GitHub overlords. It would be treated no differently than someone else trying to tamper with the written law in any form.