Ah, I think I see the disconnect. In the post you replied to, they said “copilot itself” (ie. the copilot model plus code) should be GPL’d. I missed that your reply was about whether the code specifically needs to be GPL’d. I agree with you there, but it’s also a bit of a tangent from the original point (which was that if copilot can regurgitate GPL code then it’s necessarily a derivative work.)