There was a hint that the relaunch is not certain (#msg-26396480), I think that the more probable reason is that they don't need immidiate relaunch as they already shipped some 4-6 months of supply. There is of course the less likely possibility that Teva was bluffing in the first place hoping to settle and not wanting to risk more damages (after all the litigation about the '579 patent is a though one to win, even for Teva).