Correct. And the private encryption key was derived because during encryption sony didnt use a random number at every encryption, but a constant instead. So a few math operations with the public key and tada, it you have the private key
I think you phrased that wrong. I think you're claiming that the firmware was never leaked. ChatGPT did not claim the firmware was open source. It's a pretty easy brainfart to make and say "open" when you mean "(now) public".