Congratulations on his USMAPS offer!! This is an exciting opportunity for your son!
I have not heard that the Army is offering FQNS candidates a ROTC scholarship this year. If they were I would say he would not be offered one since they made him an offer at USMAPS. Generally, FQ candidates are not offered USMAPS anyway. Did your son receive a letter indicating he was fully qualified and eligible to compete for an appointment?