Back in time, GRUB2 is using `linux` and `initrd` loader commands to load the kernel and initrd into ram on legacy BIOS. Later, `linuxefi` and `initrdefi` loader commands have been added to do the same on UEFI platforms as some kind of interim solution. These are not part of official GRUB2 code base and have been patched by the vendors.

First vendors started now to drop patches for `linuxefi`/`initrdefi` loader commands support, `linux`/`initrd` of course also work under UEFI then.

Thus, we need to adapt preseed templates to render correct templates with supported loader commands.