Not in my experience. This is how 80% of my Google Assistant conversations go:
Me: "Hey Google, play Nine Inch Nails, you know, the one in my Google Play library"
Google: "OK, playing Nine Inch Snails, a band nobody on Earth has heard of and is definitely not in your library!"
Me: (Repeat a few times, trying all kinds of accents, eventually I get tired of songs about nine inch somethings, and I pull the car over and type in by hand what I'm looking for.)
This seems, to me, to be something else. Google Music consistently avoids playing the most popular version of a song. It's always a cover by no one, or a different song by no one with the same title. I've started to think it's a royalty thing.
And what bugs me the most about the Google Play Music Library is that it won't sync up with the YouTube Music Library... They have two different music services which I can use with one subscription but I can't have some of the songs on both of them or have one single library.
There's that Google Graveyard site, maybe they should make an aaS out of it, e.g. you can do an API call with services you use, and it will respond letting you know if any of them is about to be euthanized by Google...
Me: "Hey Google, play Nine Inch Nails, you know, the one in my Google Play library"
Google: "OK, playing Nine Inch Snails, a band nobody on Earth has heard of and is definitely not in your library!"
Me: (Repeat a few times, trying all kinds of accents, eventually I get tired of songs about nine inch somethings, and I pull the car over and type in by hand what I'm looking for.)