Even if the FAA approve this lash-up it doesn't necessarily follow that EASA will does it? Or will Boeing then scream Airbus favouritism and protectionism . . . And I can't see the JCAA being pushed into something as apparently unsatisfactory as this either. Boeing seem to have modified their philosophy from "safety above all else" to "safety above all else within reason and provided it can be achieved quickly and with as little disruption and cost as possible" . . .
I for one am not going to rush to fly on it - at least on ETOPS routes.