Maybe just WAS. People in PHL can take the train to WAS or NYP to board.
The article didn't make the Cardinal sound like a done deal to me:
We would like to run a Pullman service between Chicago and New York, perhaps using the Cardinal.
A partnership with the Greenbriar folks would be interesting and probably help their bottom line. They are absolutely up front about their desire to turn a profit (duh!), it'll be interesting to see how it plays out.
I wonder if we're in for a future where private companies move in on the profitable routes to skim the cream off, leaving Amtrak as the "Essential Air Service" of the rails.