That document established the highest level of inter-ecclesial relationship possible, short of merger, among the ELCA and three large Reformed bodies (the RCA, the PCUSA and the UCC). Under it, all four recognize each other as "true churches in which the Gospel is rightly preached and the sacraments administered in accord with the Word of God," or something to that effect. Members of one church are welcomed into eucharistic fellowship at the others, and under certain circumstances even the clergy may be shared among them.
The present discussion is all about (homo-)sexuality. Again. Of course. Because what else would it be about, at this point in history? If we hope for nothing else from the synod assemblies we may yet attend, we hope someday to participate in a good old-fashioned floor fight about racism, poverty, war or the death penalty; we'd settle, frankly, for whether to patronize the Marriott hotel chain, drink Pepsi or buy Chinese widgets. Call us visionaries, but we think the time has come to put sex back in the bedroom, at least usually.
Where were we? Oh, yes: the RCA. There is a certain unpleasant irony here. Back in the day, some Lutherans -- including a younger and more fire-breathingly-high-church Fr. Anonymous -- looked deeply askance at the idea of full communion with our Calvinist partners. Eucharist, Zwingli, yadda-yadda-yadda. Basically, the FoA's language of "mutual affirmation and admonition" seemed to us, then, inadequate to resolve a long-standing division over something as central as the nature of the divine presence. In the years since, we have softened our line considerably. If Ratramnus and Radbertus could live together in a single community, we imagine that the various children of the Reformation ought to as well.
So the irony, from our perspective, is that we can "affirm and admonish" each other regarding something as central to Christian theology as the presence of Christ in the world, but apparently not over a considerably more tangential matter of moral theology. The Eucharist, after all is a sacrament; marriage, at least as typically viewed by the churches united by FoA, is not.
Anyway. The fact that the subject has been proposed (in what is called "an Overture," offered by 2 classes out of 32 -- if "classes" is the correct plural of "classis") does not mean that the General Synod will vote to discuss it, and the fact of a discussion certainly does not mean that the RCA will elect to withdraw from the Formula. So maybe nothing will happen, and maybe -- if something does happen -- it will be a discussion that brings the RCA into a deeper fellowship with its partner churches.