I think their confidence comes from the fact that they can see the numbers and we cant.
If they have sold the estimated "3 million copies" that some sources are saying...at $50-80 a copy, they have allready made well over 100 million. Now if half the people that buy the game sub, thats 1.5m subs, then you can add another 22.5million bucks per month. Well...the numbers may be a bit off, but surely not by much.
If i were a game company and made over 100 million in 1 month, then i would be confident as well. Im subbing for 6 months, as are most of my guild of some 100 hundred members.
BTW, i admit there are some massive and horrid bugs that need to be fixed. But time is all it takes.