I think ptp will stick around for a while because they are pretty desperate to have the JFK flight after Norwegian quit on that route. I would not be shocked if JetBlue got subsidies here. It would not be surprising for me if now gets added later on a seasonal Saturday only kind of flight. It was announced kind of late, so I figured a lot of it came together in the last minute. We will probably see a longer season next year. They have plenty of open slots at JFK in the winter season. The threshold to keeping this route around is not super high.
As for flights like JFK bna or msp, they could all work, but JFK slots are quite tight in the peak summer season. These would require year round slots at a time when they need to find slots for tatl flights. Unless they get more slots or JFK loses slot constraints, I don't see them adding more within perimeter routes out of JFK. Flights to pwm and btv are obvious cuts if they need to find some for European flights.
After most recent schedule extension, Boston will be up close to 15% more flights and probably 25% asm next summer over this summer. Huge growth. JFK will have even more flights than last summer even with slot tightness. And they are adding more flights to Newark and White plains. I would love to see more growth at new York. But given their slot constraints, they are already growing a lot by switching short range e90 flights for long range a321 flights. And that's before all the a220 and a321lr join fleet. That will probably usher in more possibilities.
For the past 2 years, they have been trying to control costs and steady the ship. Now they have done that and a220 is going to arrive late next year. After that, there will be a lot more places they can add.
Aside from Europe, I would think a220 allows for sna and eyw to be added. I would love to see some skiing flights out of JFK in the winter or JFK bzn in summer time. And I am sure there will be more Latin American destination opened up by a321neo from JFK. The only limit is the lack of slots. Maybe aa will be willing to sell.