Perhaps, but IMHO that’s too strong a claim.
I agree that better reasoning, testing, and agentic tooling matter, but coding models still benefit from new, high-quality code and real-world coding tasks. Software also keeps changing: new APIs, frameworks, languages, vulnerabilities, and engineering patterns appear constantly. I'm skeptical that “Coding knowledge is already baked in” is supported by the evidence.
What is the evidence that the models are already past the "transfer learning phase of learning how to code" more than they are past the "transfer learning phase of learning how to produce high quality animation or music?". The fact that code is produced is not enough evidence that "machines can't learn more from human work".
In other words: What evidence shows that code has uniquely reached data saturation? As far as I know, existing controlled studies still show gains from additional and better-targeted code training and I'm not aware of studies that demonstrate the opposite.