But with JFK slots in short supply, I wonder which flights will be cancelled to prop up the JFK-LAX service?

Perhaps under Tombstone, those of us going to SFO will transfer to a American Beagle flight at the lovely LAX RJ terminal and JFK-SFO flight go to 0.

Still will miss the 2 aisle transcon flights. Just as I miss United's B747 with 3 lounges.