These baseless speculations about ChatGPT are somewhat ironic given that the article itself alludes to what has unlocked this specific advance:

"The RDRE achieved its primary test objective by demonstrating that its hardware – made from novel additive manufacturing, or 3D printing, designs and processes – could operate for long durations while withstanding the extreme heat and pressure environments generated by detonations."

It's much easier to imagine that steady advances in manufacturing, computational modeling, and "mundane" technologies like that are contributing to progress like what's described in this article... Rather than some super secret AI assistant.

Please, folks, don't give up on reading just because computers can do it too now. :)