Heys
The pentaconn socket as directly marketed by pentaconn itself, has all its pins extended for soldering purposes
http://www.ndics.com/products/pentaconn/
On the other hand, the socket in the WM1Z, is soldered to a PCB board with the kimber cable attached as a single set (the extended solder joints seen in the original 4.4mm socket are also removed). It does not come as separate individual component. This implies that, Sony probably does not get their engineers to solder the parts together piece by piece, but probably gets them delivered in said form for quick maintenance.
As such, because these two parts are in different forms, I am unable to be completely certain that they are indeed the exact same product just specced different to suit Sony's assembly needs. For all we know, it could be a different OEM version, that does not feature the highly conductive copper core of the stand alone jack.