USB C charging happens well below the OS layer, using firmware that often isn't all that good. USBGuard or QubesOS won't help there (but will somewhat mitigate attacks trying to move up the stack)
The problem is not the charging. The problem is that a fake charger cable can run an HID attack over the +/- pins before it does a pass through to the power negotiation MCU for charging.
A tampered USB C to C cable on a conference room table can compromise people all day long.
If the USB C charge ports cut the data pins entirely then great, but I have not seen that be the case on any laptops yet.
