Well... according to BaiWei sensei， an aviation writer who works for an AVIC magazine company:
"The root of this dividing system was for USAF, and so does not apply for Navy aircraft. For F-14A, it is designed for interception and with Mach 2 capability which are clearly the speciality fr Gen.2; The A model only has TWR of 0.79, no Blended Wing Body, no standard Fly-By-Wire system. (Which is kinda similar to "High maneuverability and sophisticated avionics")
Even though it's frequently compared with Gen.4 like F-15, F-16 and F/A-18, the group is called "Teenage" that were suppose to carry the future of USA, F-14 is not a Gen.4.
It is not a shame to place F-14 into Gen.3, since that generation are with the last name of "pushing to the limit"."