Unfortunately the GAFCON Primates' response to ++Welbys' Communion to Federation initiative - see below - does not, on the face of it, look promising:
"It is on this basis that the GAFCON Primates will prayerfully consider their response to the Archbishop of Canterbury’s letter. They recognize that the crisis in the Communion is not primarily a problem of relationships and cultural context, but of false teaching which continues without repentance or discipline.
It is therefore of some encouragement that the Archbishop of Canterbury has opened the door of this meeting to the Primate of the Anglican Church in North America, Archbishop Foley Beach. He has already been recognized as a fellow primate of the Anglican Communion by Primates representing GAFCON and the Anglican Global South at his installation in Atlanta last October and he is a full member of the GAFCON Primates Council."
On the other hand, they will 'consider'. And you can bet that the ABC has previously been in contact so he probably already knows whether they are coming or not.
PS Andrew Brown gives a racing commentary on the matter along with a gallop through the history of the AC.