You’re misreading my point.Isn't shoreline east a diesel operation (though I know GCT direct trains are supposedly coming). MARC is using fewer and fewer electric locos it seems. I think once the HHP-8s are gone they're going to just be 100% diesel too.
All of the commuter railroads on the NEC have at least some of their routes electrified. The MBTA is the only one that has exclusively diesel operation, despite some of their routes having fully electrified tracks.