That's not what I said. If you washout, NPQ out, or DOR - you will be given a ground MOS. You will not be released from your contract. A flight guarantee is a guaranteed slot at flight school. If you tube your chance at flight school, you'll still owe the Marine Corps a commitment.
A likely follow-on MOS is either ground or aviation support (Motor T, Aviation Maintenance, etc.).
Ground combat slots are gobbled up at the Basic School, so if you don't make it through flight school, you are going to a support MOS.
The "good" thing about Motor T, or a lot of the other support MOS's, is that they are leadership heavy. You'll learn a lot about motivating people, managing and maintaining assets, budgeting money and manpower, etc. The downside is that if your Marines think you are too good for them and that you deserve "better" than a Motor T slot, they'll crush you (metaphorically speaking).
You obviously don't understand what you are about to get yourself into. You need to realize that joining the Marine Corps (or any other service) is about something more than getting a fixed-wing slot at flight school. We could very well be in a hot war in a few months. Use that knob on the end of your neck for something besides a ball cap holder.
You will never have a guarantee that you will successfully finish flight school. All the flight time in the world won't overcome a poor attitude. If the prospect of leading a bunch of Marines as a Motor T officer following an unsuccessful shot at flight training makes you go "ewww!", then go somewhere else.