I worked on an almost daily basis for three years with a retired USAF Colonel who entered service as an Air Corps cadet in 1937 and served through WWII-ETO/PTO, Korea, and Vietnam as a transport aircraft pilot.
He would usually say simply that he served in the US Air Force during WWII, without going into any historical details about its USAAC and USAAF antecedents. He knew that most people by the 1960s would be unfamiliar with USAAC and USAAF and would better understand USAF, even for his pre-1947 service.
It is inappropriate to attach ANY significance to a WWII veteran's use in later years of USAF vs USAAF.
Mike / KK5F