Usually the labs do some kind of post training on major events so the model isn't totally lost.

A better test is something like "what is the latest version of NumPy?"

That sort of test isn't super reliable either, in my experience.

You're probably better off asking something like "what are the most notable changes in version X of NumPy?" and repeating until you find the version at which it says "I don't know" or hallucinates.