In ignorance of this policy I've been violating it all along. They're certainly not enforcing it aggressively (though how could they if you're using your work email).
Having a workplace sponsor a separate GitHub account for your work there would be reasonable, but is this actually common practice? I certainly wish it were, for the above reason, but I can't speak to the reality.
My question was more, if I create a free account and it is linked to an organization, is that a paid account? The company didn't make my account, I did.
Without actually reading the ToS properly, I imagine you're good if your org is paying for your seat in their org (as opposed to a free org, but if it's a company with private repos I'd assume it's the case). That'd be reasonable.
If reality is that you actually meed individual billing for each individual account, that would be kind of crazy and I hope that's not the case.