I'm pretty sure he would lose the scholarship and need to re-apply for next year. I'm sure
@Montana State Army ROTC or
@clarksonarmy can give you a definitive answer. Scholarships are awarded on the basis of:
1. The expectation of the awardee reporting in the fall semester
2. How many new officers they need for the year he is expected to commission.
Since your son would not commission the year he is expected to, and will not be reporting in the fall, I think he would lose the scholarship on that basis.
However, all that being said, these are strange times; so perhaps there is a possibility of retaining the scholarship.