In the end I think we can make some simple observations about the possibility that two gospels are at work in the Communion (as I think there are)*:
(1) If two gospels remain in our midst the Communion must break up decisively.
(2) There is always the possibility that a false gospel withers away in favour of the true gospel: God may favour the Communion with evangelical renewal before a decisive break up.
*To take just one situation within the Communion, it is difficult for me to explain to myself (at least) why division among Anglicans/Episcopalians in North America has been taking place over the last decade or so if one and only one gospel is common to them all. I suggest that is a reasonable analysis of the situation, whatever view we may hold about who on that continent subscribes to the true gospel.