100% bug free software is an oxymoron. Just saying. That and - no matter what, at some point, you have to draw a line between "bugs that would block launch" and "little stuff you can pick up after launch".
If that is your standard, then prepare to get "really mad" - that said, its gonna be a million times cleaner than it would have been had it launched earlier, I can absolutely promise that (just from observation). That said, a "QA team" of several million people will ALWAYS find things that an internal team will not.
What separates good from bad here, really, is making sure there are no "big deal" issues and then how a dev team handles pivoting right into hotfix mode - how quickly and completely can they get, regress, fix, and push out those fixes. The PW team is already planning for and ready for whatever anyone - you, them, us, etc - find after launch.
That is ultimately all that any developer of any software product ever can offer. Just saying.