A direct confirmation from GitHub itself. This is problematic because Copilot sometimes outputs code that was present in its training set.
https://fossbytes.com/github-copilot-generating-functional-a...
https://fossbytes.com/github-copilot-generating-functional-a...
Most of the comments are waxing about philosophical possibilities of copilot copying GPL.
Reality is clear in the case, it's copy pasting thousands of characters of GPL code with no modifications. Copyright violation clear as day