He may wants to take Calculus I to boost his grade even though he probaly can get credit from his AP. To add his assurance, he can take ENGE1215 equivalent class from Virginia cc during summer prior to fall, he can then apply into GE by end of his fall semester if he fullfilled other requirements.
http://www.enge.vt.edu/_files/undergraduate/pdf_COM_Requirements_Policies.pdf
As tou can see, if students bombed their grades during first year, it doesn’t matter if you are in IS nor GE anyway.
So if your son decides to try US at VT. I say he can do this well with careful plan in advance.
Good luck!