P used for something in places in parallel of hundreds of (several exotic, rarely used) technologies is not really predicting how much P was used without scientific and ML uses. What if P is mostly used for scientific and ML purposes in those places, or as an experiment, study, not necessarily being a backbone? Or with other secondary agenda, overstated, etc. The mere fact that P is used in a huge amalgam of A,B,C,... tells very little alone concerning the question. Almost nothing.
It's not solely used for scientific and machine learning at any of the aforementioned companies. It is the (or was) chosen by a number of technology companies who have the resources and knowledge to select the correct languages to address one or more of their existing problems. That is evidence of use and use case.
I would argue moving away from Python at global scale doesn't even negate my point. All products change with scale.
... do I really need to explain this?