I've not seen Copilot in action yet, I was under the impression it doesn't use code directly.

In any case my original question was answered by the tweeter in a later tweet I missed https://twitter.com/eevee/status/1410049195067674625

I get where they're coming from but they are kinda just handwaving it back the other way with the "u fell for marketing idiot" vibe. I wish someone smarter than me could simplify the legal ramifications around this but we'll probably have to wait till it kills someone (or at least costs someone a bunch of money) to get any actual laws set up.