For sure! I mean, my Google pixel has "Now Playing" which is able to passively listen to the microphone for songs it knows, and displays them on the oled lock screen.
So, we already know that it is
A. completely feasible for a smartphone to do this.
B. At least a subset of smartphones have always-on microphones.
Maybe not a remote control... But why would you put it in a remote anyways when everyone has a phone?
I'm not sure I believe strongly either way, but after a few drinks I often convince myself it has to be happening due to the prior proof that it's possible, and the fact that if I were at the right place in one of theses companies, I'd do it just to prove that I can, and do it in a way such that the least amount of people internally would know about it.
But that may just be the conspiracy theorist in me.
So, we already know that it is
A. completely feasible for a smartphone to do this.
B. At least a subset of smartphones have always-on microphones.
Maybe not a remote control... But why would you put it in a remote anyways when everyone has a phone?