Depends. If you find useful code on Github, Stack Overflow or anywhere else in the internet, you still need to check whether it is suitable with your licensing or not.
If you find useful code on Github or StackOverflow, you can check for the license directly there, or you can try to find where it was copied from, and look for a license there.
Copilot isn't copying, it's regurgitating patterns from its training dataset. The result may be subject to a license you don't know about, but modified enough that you won't find the original source. The result can be a blend of multiple snippets with varying licenses. And there's no way to extract attribution from Copilot - DNN models can give you an output for your input, they can't tell you which exact parts of the training dataset were used to generate that output.
But Copilot won't accurately tell you if it's directly copying code, and if so what the license is. If it provides MIT licensed code that I then need to include, how do I know that? Do I need to search for each set of lines of code it provides on GitHub?
When a person gets code from another source on the internet, they generally know where the code has come from.
In a real world scenario you wouldn't be mindlessly pressing Tab right after linebreak and accepting the first suggestion that comes your way. While entertaining, nobody gets paid to do that.
What you get paid is to write your own code. When you write your own code, generally you think first and then type. Well, with Copilot you think first and then start typing a few symbols before seeing automatic suggestions. If they are right, you accept changes and if they happen to be similar to any other code out there, you deal with it exactly the same as if you typed those lines yourself.
If you use it as a programming partner it will simply autofill whatever you're writing line-by-line. You're not forced to use code completion at a whole-function level and it's not even the suggested use-case.
Code completion that can suggest the whole line instead of a single word (e.g. often it guesses function parameters and various math operations when you haven't even typed function name yet).
