Other than players who sign an LOI and whose grandmas aren't fake-sick, who is ever 'committed' officially?
And LOTS of players turn their backs on schools who helped them get their name out there. Kolin Hill is thinking of doing just that. Zack Mattin's lil bro did it to Kentucky. Danny Spond did it to Colorado. TJ Jones turned his back on Stanford. Golson turned his back on North Carolina. This list goes on forever.
As for Mckenzie, well, you can believe what you want about ND being the only school to notice him, but that just isn't true. A kid with his incredible highlights playing in Florida for a school on TV as much as his school did, that kid would have been noticed for sure. ND was just the first of the big boys. And he repaid them by getting interested in other schools as soon as those big offers came through, despite reports that he is qualified for ND (I've heard otherwise, Mike a frank eluded toit as well on Power Hour).
I hope he signs with ND, but to say its out of the equation that he signs elsewhere, again, is being blind to the realities of the situation.