Open source is usually referring to the OSI definition which is essentially identical to the FSF “free software” term.
And by that logic, gpt3 and dall-e are also copyright violations. Except this has never been proven to be the case.
I literally use “libre” and “gratis” to make that precise distinction.
And it’s at best questionable whether copilot is derivative of the code it is trained on.
Copyleft, free software, GPL style licenses do not have their source open purely for the purpose of studying and modifying. Their licenses also require that derivative works also be free and that such modifications be distributed.
Copilot does not comply with this. And so violates the spirit of those licenses, and probably also the letter of the law.