The term "kinked shell stakes" might well be specific to Global Connector Technology products.
In general, those metal tabs are used to enhance the mechanical strength by which the USB or other connector holds onto the PCB - thus preventing or at least reducing the chances of some accidental pressure or impact shearing the connector off the board, tracks and all.
The tabs are typically inserted into routed slots in the PCB, and then mechanically bent inward on the other side. The "kink" provides a snap-fit through the slots, at least until the bending is done. No, those holes would not be drilled, but routed.
Many connectors use straight tabs instead of kinked ones, so they aren't ubiquitously kinky. The kink makes it simpler to position the device at a precise repeatable height off the board and also to make a bend at a precise position along the tab.
If the metal shell needs to be connected to say a ground trace, there needs to be a solder pad on the far side of the PCB, such that the tab, when bent inward, contacts it. This then gets soldered.