that’s cause bethesda has a tendency of making up dates, even before the game was even finished. Remember ETQW? When the release date was “when it’s done”?
For this game, I have never heard of a release date called “when it’s done” that id software games and 3d realms games usually use. Blizzard has the “As soon as we are finished with the game, we will let you know”.
So really, a date from bethesda really means “when it’s done”. The only way to find out the actual release date, is to get the “gold” status from SD, and a release date, when the game hasn’t upgraded to beta yet, always means “when it’s done”.