IANAL, but I wouldn't read that as granting GitHub the right to do anything like this. There's definitely a reasonable argument to be had here, but I think limiting the grant of rights to incidental copies should trump "[...] or otherwise analyze it on our servers" and what they're allowed to do with the results of that analysis.
On the extreme end, "analysis" is so broad that it could arguably cover breaking down a file of code into its constituent methods and just saving the ASTs of those methods verbatim for Copilot to regurgitate. That's obviously not an acceptable outcome of these terms per se, but arguably isn't any different in principle from what they're already doing.
Ultimately, as I understand, courts tend to prefer a common sense outcome based on a reasonable human understanding of the law, rather than an outcome that may be defensible through some arcane technical logic but is absurd on its face and counter to the intent of the law. If a party were harmed by an instance of Copilot-generated copyright infringement, I don't see a court siding with this tenuous interpretation of the ToS over the explicit terms of the source code license. On the other hand, it would probably also be impossible to prove damages without something like a case of verbatim reproduction, similarly to how having a developer move from working on proprietary code for one company to another isn't automatically copyright infringement.
I doubt that GitHub is doing anything as blatantly malicious as copying snippets of (GPL or proprietary) code to explicitly reuse verbatim, but if they're learning from license-restricted code at all then I don't see how they wouldn't be subjecting themselves and/or consumers of Copilot to the same risk.