> _"I recall a single product category page would confuse Google into thinking it was a product page"_
That's not something I've noticed being an issue for a very long time already. However, until not so long ago it did occur that no matter whether you marked up a single or all products on a listing, Google would generate a Rich Result (inc price, rating, etc) based on a single product.
This is an issue Ryan Levering is aware about and of which he is of the opinion that it should have never happened (call it a glitch in the matrix). I'm just not sure whether he has come around to fixing that bug yet.
Though whether he already did or not, the Rich Result based on a single product (out of many) doesn't imply Google only understands listing pages as being about a single product. It's nothing more than a 'rendering' glitch on the frontend.