Reproducing copylefted code is neither indexing nor analysis.

To be clear, a piece of code that creates a copy of some GPL code is not a problem by itself. However, it's misrepresented as something the tool "generated" rather than code belonging to an existing human actor, without appropriate attribution and licensing info.

I think we're assuming that they used GPT3 (or whatever) on code that was stored on github.com in accordance with their TOS, which means (if I understand correctly as a non-lawyer) that they didn't share it under the terms of the GPL, since they can't, but if whatever licenses the code already had attached were not sufficient, that code was also licensed to github for the purposes of indexing, analysis, and sharing with other github service users.

Does this mean that if you picked up GPL code from gnu.org and put it in your public repo, you're in violation of the GPL for illegitimately licensing that code to gihub under a non-GPL-compatible license? Maybe!

> that code was also licensed to github for the purposes of indexing, analysis, and sharing with other github service users

Even if said code was licensed to Github for sharing with other users (e.g. displaying it when another user browses the page), that doesn't mean that the same permission is given to all other users under the same conditions. Or allows them extra liberties, like using said code for purposes other than "sharing with other github service users".

No argument, there! I'm pretty concerned about the consequences of using Copilot, legally. It all seems to turn on whether a judge or judges believe that a long sequence can be produced by "learning" rather than "copying". ¯\_(ツ)_/¯

It's irrelevant. There is no guarantee that the people uploading code even have the ability to grant github such a licence if they aren't the copyright holders.