Doesn't matter that it's a technical preview; people are using it now, GitHub has already used it internally. So if it infringes now, there is already code out there being used that does infringe.

GitHub appears to be tracking every snippet that they're generating during their trials:

https://docs.github.com/en/github/copilot/research-recitatio...

Are you doing that? If not, then I wouldn't use GitHub's use as justification to engage in copyright infringement.

Oh, I am not using Copilot. But other people not part of GitHub are. And those are still violations.

How will it find the “correct” license?

Will it check the LICENSE file? Simply having a LICENSE file is not a declaration that all the code in that repo is under that LICENSE.

What if specific lines/files are specified to be under different licenses?

What if the publisher of the repo is publishing it under an incorrect license in bad faith?

Will github be responsible if it tells me the wrong license?