It may very well be that.... just as taking the hose end off an R-12 fitting does.... that extra fitting has to actuate the inner old fitting ....without some super long shraeder actuator being attached to the r 134a hose end...
Or they may have removed the Schraeder valve from the old inner fitting....

This may be normal except if you have Service Fittings... where the hose goes into one side and the little square drive is on the other... those are built like the valves inside a manifold guage set...