And the minute they fail to meet that date or announce it's pushed back, whiners will created threads about how Bethesda lied to them
Seriously, I've even seen it when a general rather than specific date is given.
When Bethesda announced that they aimed to have the Fallout 4 Creation Kit released in the first quarter of 2016. Most people reasonably took that as they intended to release it sometime in January, Febuary or March of 2016.
Yet, within minutes of midnight passing on January 1st, there were dozens of threads screaming about Bethesda lies and where's the Creation Kit and they aren't releasing one because Microsoft and Sony have said no to modding and Bethesda have abandoned it for PC too. Even when Bethesda reiterated sometime in the first quarter of the the year and people pointed out Bethesda had given no specific date, the threads continued.
When Bethesda said they hoped to roll out mods for Xbox in June of that year. Minutes into June the 1st, the forums were littered with threads again. Bethesda lied, modding on xbox abandoned etc.
That's why Bethesda try to avoid specific dates these days. Not that they did give them before. Game releases really being the only definite ones and thats because the retailers need to know when to start displaying them for sale and when to stop pre-orders..