Something odd happened yesterday. 

I was perusing through the settings on my LG G4 within the Google Play Music app, tapped my email address, this brought up another screen with an offer to try All Access on a trial basis for free for 6 months. It had some text re being a Samsung phone which was even weirder. 

Previously, I have had 2 free trials from Google Play Music All Access, and have not been able to redeem any offers on my account since. 

Since I discovered this I am aware of a few others who have also been able to activate the trial. So maybe it’s worth checking your own android phone now.