If apple came out with their own linux distro, with open drivers and a mainline kernel... A girl can dream!
I feel like Apple wouldn't want to make full Linux work on their hardware, but they could enable their Darwin kernel to emulate Linux syscalls and provide a way to boot into a mode that basically loads the kernel and whatever Linux shell you want
This path is already taken and it didn't sell Apple hardware in masses.
The memory that XNU and Darwin are technically open-source projects is a curse that brings one only suffering.