I'm all for being skeptical, but it doesn't take too much digging to find the proof (it's in the original tweet thread): https://github.com/Kuberwastaken/hp-laser-1008a-macos

But it's not completely native, it's a wrapper around the original linux driver (or parts thereof) running in a container.

Still better than nothing.

That runs the original HP driver in a Docker container, using two minuscule Python scripts.

Bro is marketing it as a (native) MacOS driver.