I think what that poster meant was that if you wanted to originally book an MK view, and they were sold out, for example, you can request an upgrade to MK view *if it is available at the time you arrive* with the understanding that you are willing to pay for it. That note can be placed on your reservation.
However, when such a note is placed on your reservation, but the view you wanted never does become available, a CM may see that, and notice that there STILL might be a better view than what you have booked is available, and upgrade you with no charge.
I'm sure the poster did not have a note on their reservation "free upgrade requested".