In other words, do R-1234yf systems use the same charging port design as R-134a?
No, they are not. According to this website:
Vehicles with R-1234yf have different service fittings than R-134a vehicles to prevent cross-contamination with different refrigerants.
You can purchase new couplers which will convert the old R-134a gauge manifolds to the new R-1234yf couplers.