Well, this is why the adapter market exists in the first place.
A quick glance into the upcoming, modular 2019 Mac Pro, which Apple stated could be upgraded with new components, features custom SSD connectors that will have to be purchased from Apple.
The leaked shot reveals that the SSD connectors aren’t industry standard, and do not feature a standard M.2 pinout.
Apple has declined to speak about the slot’s pin compatibility with older Apple SSD modules, leaving open the possibility that Apple is using a proprietary new connector.
Stay tuned for additional new details as they become available.
Via The Mac Observer and AppleInsider