Of course he has the right to take the day off from working on it(which I dont think he did), he just doesn't need to put up a third teaser with no clarification on twitter if its not actually imminent.
He could say hes been overwhelmed by it and is going to take a week off and then get back to it and I wouldn't complain at all, its his project. Its the perpetual state of "any day now" thats a little annoying since it would take so little effort to squash it.
He can't give us an exact day or time because these things never go according to schedule. When you are about to release something like that, you do a last minute testing and find a bug that would take you off schedule, people would be upset again. This is why things like that don't have schedule or even approximate dates.