You never know where a heart pushes a guy. Obviously, it's all these guys dreams to play in the NFL. However, I believe if he goes with his head, and he comes across to me as a very smart and thought-out guy, I think he stays (assuming he gets the approval soon).
Scenario A-He goes pro-He's projected to be a mid-rounder at best, so NFL best case scenario for next year, he is a backup. Additionally, even if he makes a team (and I am a fan of his and optimistic he would), NFL contracts are not guaranteed and they can drop him whenever they want. If he doesn't make the team-he gets nothing. Don't forget, even if he's good enough, he can get injured in camp, have some sleeper QB ball out, or have some organizational politics play a factor.
Scenario B-He gets over a million dollars guaranteed to be the face of a Major College Football team.
Best case scenario-He balls out again with even more hype after this season, makes the NFL in a year and develops and becomes a starter.
Worse case scenario-He doesn't make the NFL, but has another 1-2 million dollars in his pocket. That's a pretty good start to your post-college career.