Totally agree, the first "estimate" was a massive release window which was a whole quarter of a year, which is absolutely fine. If you can't make that then either something must have happened, or you really don't know how to judge your work on an ongoing project. The REAL issue is that as that window was closing a specific single date was given. If you can't hit target dates the solution is not just waving a blanket statement of "Release dates are estimates and subject to change at our whim" it's to stop giving dates all together or, if you really want people to stop asking, replace it with just a progress bar.