Reading the comments, it seems the overlooked word is “depreciated” meaning users will have time to properly transition their hardware.
It seems the proposal suggests an opportunity to revisit the boot-loader like the heavily downstream patched grub2 deeming too complex to maintain in long term. Additionally, this proposal gives time to explore alternative boot loader like  systemd-boot (mainly for x86-64 architecture and useful for desktop and workstation) and  rEFi (?) to further reduce the code burden.

-- 
Luya Tshimbalanga
Fedora Design Team
Fedora Design Suite maintainer