I think this fits the analogy of the philandering husband lecturing his estranged wife on fidelity. When he was busy having affairs, he understood the vows to say that he "may" be faithful. After his wife left him, he interpreted them to say that she was "required" to remain with him.
I don't see the ELCA has having any affairs. They haven't turned to other gods (although some claim that about one congregation in San Francisco, but they aren't using ELCA materials).
A husband
must be faithful the vows and the rules of marriage, he must remain faithful to his wife. Within those rules there are many "may" clauses, he may be the one who takes out the garbage, changes the oil in the cars, mows the grass, has an every Friday night date night with his wife, etc.
There are rules within the ELCA that congregations and clergy and bishops must follow, e.g., 2/3 majority vote of those present to terminate their relationship with the ELCA. If those rules are not followed precisely, the bishop declares that the congregation remains part of the ELCA. (I've heard of cases where bishops have helped congregations to properly follow these rules so that there are no misunderstandings about what must be done to leave the ELCA.)
There are also many "may" rules -- especially in terms of disciplining congregations and clergy. Congregations are not to call non-rostered pastors without permission of the bishop. When they do act contrary to this rule, the bishop
may call for the removal of the congregation, which only requires a vote of the synod council -- not the whole disciplinary hearing process (see 9.23.). In nearly every case, bishops opted not to discipline congregations who had called ECP ordained clergy who were not on the ELCA roster. Prior to 2009, there were very few
rostered homosexual clergy in committed relationships. Most of those in the news, e.g., Jeff Johnson and Anita Hill, were not on the ELCA clergy roster prior to 2009. They were not subject to disciplinary actions by a synod bishop.