Agreed.
> Stop trying to make this into some abstract argument.
As you mentioned, it's not an abstract argument. It's statements of fact.
> A vast (and growing) amount of source code is more open...
No, not at all.
1) If you honestly believe that major tech companies will permit both copyright- and license-washing of their most important proprietary code simply because someone ran it through an LLM, you're quite the fool. If someone "trained" an LLM on -say- both Windows 11 and ReactOS, and then used that to produce "ReactDoze" while being honest about how it was produced, Microsoft would permanently nail them to the wall.
2) The LLMs that were trained on the entirety of The Internet are very, very much not open. If "Open"AI and Anthropic were making available the input data, the programs and procedures used to process that data, and all the other software, input data, and procedures required to reproduce their work, then one could reasonably entertain the claim that the system produced was open.