Friends won't show up on my list after request was sent and the other party accepted it
This is a bug. While the specific cause for it is still unknown, in most cases (but not necessarily all of them) one of the two users who recently became friends can see the other on their friend list but the other can't. In most cases it is the user who sent out the friend request who is unable to see the other user on their list when they accept it.
It's nice to see that I'm not really going insane. :D"
how are we going to deal with that bug without making a new acount?"
Just wait it out, as making a new account won't resolve the situation anyways.
August 21 could definitely happen. People might say that it'll be two weeks before it's retail release (so the 28th for the demo) since that's what Madden and Tiger Woods did, but Madden and Tiger Woods don't have any direct competition, and NHL2K9 has already released their demo. This differs from last year substantially since NHL 2K8 didn't release their demo until after the retail game hit store shelves.