After more research (1!, 2) i think that it is likely that these new computers will no longer support legacy BIOS/CSM, 32bit, MBR.
These possibly support only EFI and GPT, so i guess focus should be on how to convert current system to be EFI and GPT.
Though i am unsure if i should follow that commands exactly as mentioned, especially:
sudo grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=manjaro --recheck
is correct and how to properly:
create an ESP (EFI System Partition).
It is a FAT32 partition which has the .efi files for booting, which you can create using Gparted or gdisk. (Size 200-512 MiB).
Update: i have updated first post of this topic