If you dont ask, you don't get. It cost nothing to ask, and you may have gotten $600 plus an upgrade. Zero downside, plently of upside.

Depending on what I was going there for or what the situation was, I might have taken it. If you're already stuck in Y anyhow (even if its 17B) you could always wait until they unblock seats and probably get a decent seat just before departure. Or the next day there may be different GA's, and they may take care of you after you give them the story.