After poking around with the example code in the docs and your code above in JS Bin, I can confirm this behavior as existing and being confusing.
It appears there’s a clear contradiction between what the docs claim you should be able to do with embed.getPlayer() and what’s possible in the browser:
console.log(player.addEventListener);
// undefined
Fwiw, the docs here don’t show an example for calling addEventListener on a player instance, but I think your usage is a reasonable expectation.
I could certainly be missing something, but this seems like a bug or is otherwise unintended behavior.