I just mounted an iso and saw grub files, weird… Maybe only the package is installed, let me check here a little bit and i’ll get back to you.
ok, you’re right, yesterday i booted the image.
If you boot the iso (Antergos) you’ll see /boot/grub, but that means the file only appear after the image is mounted. ￼
I also do’t know if there is some file missing.