Despite the CPU being 64-bit, the distro MUST be 32-bit. This is because of the MacBook’s BIOS, which prevents 64-bit bootloaders from working.
That’s the thing, you can run a 64-bit distro as long as you’ve a 32 bit grub starting it :) You run Debian 12 amd64 on a 32 bit EFI:
As of 2023 and Debian 12 the amd64 installation media (available in netinst form) includes the UEFI boot loaders necessary for both i386 and amd64 boot. By selecting “64-bit install” from the initial boot menu, debian-installer will install a 64-bit (amd64) version of Debian. The system will automatically detect that the underlying UEFI firmware is 32-bit and will install the appropriate version of grub-efi to work with it.