Well there is either a bug in the RC, or Apple stripped customer notifications without warning.
I can still use my custom ringtones for the actual phone call, but now under messages/voicemail/etc I can’t see ANY of my custom tones, only the iOS installed ones.
And simply going into the menu to look at tones changed it to None even though I didn’t select anything. So if you use a custom tone for anything other than phone lines, do not go into those options or it defaults to none.
Assuming if you bought official tones they would still be there, but I don’t have any of those.