That's definitely the next logical step in his thinking, and I think the author is indeed aware of it...hence he calls it a major development.
If Williams decides to take this route, this *is* big--something this drastic definitely has to happen. If relations with Rome and Constantinople are to move to a higher ecclesial level, there *must* be firm discipline within the Anglican communion. TEC cannot be allowed to "reform" the historic faith at will...they have to be stopped, and the orthodox Anglicans in the US have to be vindicated *by the official Anglican Church*--not just by their own consciences.
As this Roman sees it anyway, Anglicanism faces a stark choice--ecclesiastical chaos, or being willing to level anathemas at the revisionists in TEC: "If he will not listen to the Church, let him be to you as a heathen or a tax collector".
Nicely summarized.