I neither see it "stealing". The neuronal network was trained with code as input. It's creating code as output. The output has nothing to do with the input once it is trained. Do people dont know how neuronal network work?
It's like saying GPT-3 created text is copyright infringement, because some author used the same sentence in a book before.
1) Copilot is not designed to output the source code for a project source file
2) It does not re-create the whole source code, just parts of it (sentences, not chapters)
3) The source code license, e.g. BSD, works on "the code" - copying a line like "void main(void) {" will not trigger it, obviously
It's like saying GPT-3 created text is copyright infringement, because some author used the same sentence in a book before.