Nothing.
You get a downgrade, you get a refund of the difference.
You're certainly not owed anything else.
Now, if you wanted to explore other options, you might look for F on JAL via Narita, or I think Singapore does the route nonstop. But oh wait, Alaska can't actually be bothered to make mile redemption on Singapore a real thing, so it's still just an imaginary benefit.
But I'm not sure what you were getting at in your original question. If you're seeking some sort of compensation, then no, you're not entitled to anything but the fare difference.