Putting a license on a comment isn’t how licensing works.
One party can’t unilaterally decide we are in a contract (what a license is).
If they moved their comment behind a wall and required clicking “I agree” then it would be a valid agreement.
It’s the same thing as people posting “don’t use my data” in their Facebook wall. It’s not how legal agreements work.
Any AI crawler will just suck up their data regardless of them putting a license in their comments.
If they truly want to stop AI from using their comment, they should advocate for a more robust robots.txt on their instances server.
Numpy uses Fortran