This means that the development of the game is complete and that the physical copies are ready for production.
Yeah... riight!. It would be stupid to believe the game is actually "Complete" just because it goes gold. It's not like the AAA game publisher's have been releasing games in an unfinished "we'll fix it later; in the meantime give us your wallets, and we MIGHT go through with it" mentality for years. It's definately complete and in a completely bug-free, optimized state. Look at the version on Cyberpunk's disc from when that game went gold. It's perfect!