[Maursault]

> Maybe. But graphics cards aren't the only thing people put into PCIe slots.

Right, so there will be PCIe slots for expansion, they just won't support PCIe GPU, just like Thunderbolt PCIe expansion chassis for Thunderbolt now. It isn't the PCIe slots that break compatibility, its the difference in architecture between x86 and Apple Silicon that makes them incompatible.