Eventually, you'd probably be notified by your ALO. But as BSA said, if it's a presidential, you probably will just see your status online change to "Appointment Offered" and then you'll get a package in the mail. And yes, your MOC will be notified; but that notification won't be necessarily about you. It will be about which applicant their slot went against.
But a lot depends on the nomination. I.e. If your MOC ranks their slate, and you are the #1 principle nominee, the academy 99% of the time, will give you the appointment with the MOC nomination. This way THEY, the academy, can use the presidential for someone else. But if your MOC doesn't rank their slate, or if you were #2-#10, then if the academy wants you, they'll probably have to use the presidential for you because your MOC can only have so many. So the answer to your question is: "It depends". Which nomination used depends on the nominations available, how your MOC's nominations are set up, and which applicants have what scores. Basically, there isn't just 1 way for this to be done. Best of luck. Mike....