I want to add that the Google Sounds functionality worked fine a couple of weeks ago, when I had tested it earlier. It even worked with and without the Internet permission toggle.
I would have been prompted to select a default app with which to select a ringtone. The option is no longer there when I have tried testing it with the two latest versions of the Apk that target android 15 from Apkmirror, using both GOS stable, pre Android QPR 1, and and GOS Beta with the upstream changes.
The intended behaviour would be for the select default app screen to appear and for the user to be able to select either the stock sounds app or Google's one.