>>davidg+(OP)
This exact code can be found 1000 times on github and many of those are MIT licensed https://github.com/search?q=%22cs+*cs_transpose+%28%22&type=.... Copilot, or any other developer or person, has no way of knowing where the original implementation came from or it's original license. The cat is out of the bag, get used to it.
>>nights+oY
This scenario is specific to neither github nor copilot. It will always happen for any combination of a code generating LLM trained on all publicly available code.