> I was writing that intro based on recalling Andrew Kelley stating in a video
When you are writing for a technical crowd, it is good to be prepared with references and evidence. Unsourced information is likely to be questioned. Unsourced information making dubious claims that go against half a century of computer programming and practice is even more likely to be questioned.
> Can you say for a fact that no language designer expert ever told Andrew Kelley this?
That's not a valid counter-argument. Can you say for a fact that Russell's teapot does not exist? That does not make the existence of Russell's teapot any more likely! The burden of proof lies on you to show that the bold claim you made in your article holds up against scrutiny.