Clean room design is a technique to avoid the appearance of copyright infringement. If the courts were omniscient and could see into your mind that you didn't copy then there would be no need. Why this is relevant is because we can see into the mind of copilot. Whether what it does it considered infringement I think will come out in the details.

If the ML model essentially is just a very sophisticated search and helps you choose what to copy and helps you modify it to fit your code then it's 100% infringement. If it is actually writing code then maybe not.