The premise
Even if a company had a policy where promotion was impossible without education, and any employee after a set time who didn't get promoted was summarily fired, this would still never happen.
He's clearly a good employee. They would have made him aware of the policy long before this (like when he was last up for promotion and lost it to the bozo), and given him the opportunity to upgrade his education in his spare time.
You don't just throw away your 8-time Employee of the Month due to a policy loophole, especially in a business where employee turnover is a problem and most employees hate their job, performing with minimal effort.