Likely the process is to provision the PC using an AD account, setup a local account, and then disconnect from the network forever. Microsoft isn't going to step on the toes of businesses that need local accounts but they really don't care about upsetting individuals
In reality, truly airgapped PCs are rare. They are usually just there to run some specific application that likely can't run on anything safe to connect to the network. Unless you're both the admin and the only user, an airgapped PC is disadvantageous for security reasons. There's no one monitoring what the users are doing with it, how do you know if anything malicious is running on it if the only reference you have is the PC itself? It's like owning a single clock and never checking to see if the time is actually correct. You're more likely to find airgapped networks that allow for monitoring of the hardware and what users are doing with it. Of course there will always be things like malware testing but with how smart malware is now, it's pretty good at detecting when it running airgapped and won't actually do anything until it knows it can phone home.