No because this is all about haggling, there are obviously things being negotiated that we don't know about. They will agree on some common ground. It might not be about engine size. After all not even the teams are allowed a copy of the concorde agreement so we really don't know what they are arguing about.
They obviously want something out of it and this game continues until they get what they want. The same is true for mercedes who are threatening a breakaway.
As I say if they think F1 will be ok without them, offer them the new agreement and say deal or no deal. Of course it wouldn't die but a breakaway series with them in would be very bad for F1.
This is exactly why F1 cannot be run by the teams, they would never agree on anything.
As for porsche, you proved my point for me. Ferrari doesn't need F1 just another form of racing. Just like Porsche doesn't and has rarely ever needed F1.
