The judge is still out on the licensing issue. And given it can, at least sometimes, output verbatim copy paste, including comments, of well-known GPL code[0], well, let's just say the issue is not clear-cut.
Copilot's api and suggestions could easily (and maybe was?) implemented as a SBQA style model. Using a search engine to find promising examples/context followed by a transformer model to synthesize the final output.
Attribution would clearly be required in such a search derived model.
