Afaik Google play music doesn't work that way - it only plays whatever is in your account online - I have uploaded over 5,000 MP3's to my account and I can play them but it doesn't read the files locally

VLC player and maybe some others should be able to see them and play them

https://www.google.com/search?q=upload+to+google+play+music&oq=upload+to+goofle+play&aqs=chrome.1.69i57j0l3.12177j0j7&client=ms-android-mpcs-us-revc&sourceid=chrome-mobile&ie=UTF-8

Or

https://support.google.com/googleplaymusic/answer/1075570?hl=en

No I don't think so