Annoyed more so than sad. For the most part, I listen to instrumental songs to block out the ads and music while shopping. Otherwise, I don't play music.
I do have several nature recordings of thunder storms, crashing waves, etc that could fill in if music was gone from the world.
The upside for me would be no more music in tv shows and movies. Sometimes, its too loud to clearly hear the dialogue.
"On modern Android phones, there shouldn't be any problems as long as you choose to factory reset your phone through its settings. This will automatically remove all the associated accounts in a way that "frees" the phone from FRP. If you try to reset a phone through the bootloader, FRP will kick in, and it can't be set back up without the previous account's password.
I assume if I tried to reset through the bootloader the phone would become a paperweight as there isn't a Google account on my phone. No password to enter. I'm just going by what android central says, haven't tried it myself. Sounds like you have more experience with this.
Only a few email services respect user privacy, anyway.