Constitutions are scraps of paper which can be ignored by the revolutionary. If they need to pacify a broader base, they can always change the document, but the radicals in the PCUSA have found it more effective to just ignore their constitutional standards which stand in the way.
Moderates often delude themselves by thinking that since they are operating in good faith, the radicals are as well.
I'll give you a specific example of that, again from the Presbyterian side. When the southern and northern churches were negotiating the merger that became the PCUSA, the southern churches were told that they would be able to continue to leave with their property (a right they had always had) if they didn't like the merged church. Shortly before the merger, that provision was pulled in a closed door meeting. Most of the southerners would not have learned of that until it was too late, but the lone liberal with a conscience called and tipped off one of the conservative leaders. (With the secret out, a difficult and limited exit procedure was put back in as a number of churches rushed to try to meet the deadline before the new plan went into effect.) And that's how the PCA was born.
This is probably the Episcopal equivalent of that phone call. Someone leaked this as a last warning to the moderate bishops. They can act now, or they can peacefully sleep until the Night of the Long Knives.
Ugh. You're probably right.