I think that the EFI argument is something of a red herring, no one is suggesting a return to the Quadrajet.

OTOH, EFI can be done as a modular (and replaceable) product rather than as part of monolithic whole-vehicle design, but that last bit of goodness or regulatory need is likely not met.

I just think of it all as being Peak ICE. The last generation of piston engines is going to be crazy complex and probably deserve to be usurped by it's battery-powered successors.