Since softwareupdate now requires a secure token regardless of how it is used on Apple Silicon the user can elect to simply not install updates. This makes softwareupdate pretty much useless for forcing users to update their Macs.
The other options I have seen dont seem to be much better. Automatic updates seems a bit unintuitive, and from what I am reading “schedule an update” is not yet fully supported in JAMF. How are you guys doing things in relation to macOS updates?