It is 100% related to his company’s income tax footprint. If they have an employee in a state, they almost always have to file corporate income taxes in that state.
If they don’t have an employee there, they may have very good and legal reasons to not file there.
The issue is as someone who’s not exposed to corporate taxes and works on the company’s tax returns, you have no idea just how much of an issue this can be. Say your salary is $100,000; you think what’s the issue, I only cost the company that much… Your dumb ass just moves into a state where your employer said you can’t work there. All of a sudden, the company owes $1+ million in taxes they weren’t on the hook for before because they have to file a combined unitary tax return. You didn’t being just your stupid ass into the state, you brought 20 other companies into the state.
Go ahead and absolutely move. When your corporate tax department finds out, your ass will get canned.
I got into Pratchett way too late and I’m so sad about that. On the upside, I get to experience his books with the knowledge I have in the world so I can really appreciate it for what it’s worth.