Nvidia Arch user here, are you just forgetting to rebuild your kernel modules after a kernel or nvidia driver update?
You can just add a pacman hook that triggers mkinitcpio -P after the linux or nvidia packages are updated. I've never had a no-GUI situation from a stray update... maybe one or two that were my own doing when trying to set up UKI's though.
I just followed the note that's mentioned on the top of your link and installed the Nvidia driver as dkms package. I originally did that because of trouble with a new driver version and temporary downgrading is much smoother with dkms.
Also never had issues with the DE starting properly after upgrade since then.
I'm usually using nvidia-beta drivers from AUR because they're newer, so I just added the hook as an insurance policy.
The DKMS drivers are probably the safer option because they'll handle rebuilding the kernel modules. Even though (like EddyBot said) the kernel and nvidia packages are supposed to get updated together, sometimes you can spam pacman -Syu at the wrong time and only one package is updated and things go wonky...