I’ve always had a pet theory that knowledge itself is an evolutionary force and some things like this follow that path.

I’m folding your idea in.

We now have access to a staggering amount of art.

In, say, the Middle Ages, few people owned illustrated books, even fewer owned art like paintings. Many people never left their own town, so if you weren't in Rome et al, you were on your own artistically. Things can get weird (like these cats).

Well yeah, Descartes didn't appear in a vacuum and neither did Michelangelo...

On second thought, maybe Descartes, wasn't the best example to use. But he didn't truly arise in a vacuum, he just used one as the starting point for his thought-experiment...

There were amazing sculpters and artists, but I think anyone with talent had a rare chance of being born rich and honing that skill set. So maybe these were just the palace's beat artist on hand? The human faces are just weird though. There must have been a reason

I want to say that's it's moreso just a case of technique ever-improving. Also a case of a certain art style being en vogue and normalised, suggesting that a more physically accurate-looking cat might have been less welcome or expected than the style of the day.

You can add "expression" to that second point, also.