It was just a joke. Big T gets it. As far as your irritation at the situation. Plenty of folks got the starfield code no problem. There were forum posts discussing if we had to wait or not. If we had to have AMD hardware to redeem or not.
While I do not remember seeing “REDEEM BY THIS DATE OR ELSE” anywhere, I didn’t read the terms or conditions.
It sucks you missed out, but you’re making a big deal out of it and it is your own inaction that led to you missing out. As far as legality, I’m not Australian and can’t comment, but I would think the reply might be something like the date to redeem by was in the terms, you didn’t read them? well.