At one point, The Binding of Isaac: Afterbirth+ was going to be a launch title on the Switch, but only a few weeks prior to the date, the game’s devs announced that there were production delays and a vague date of March 2017 was all that was given for its release.
Today, Nicalis took to Twitter to give new word:
— Nicalis, Inc. (@nicalis) March 8, 2017
The date may not come as much of a surprise, as Gamestop and other retailers had this listed on their sites for the new release date, but this makes it official. If you had previously pre-ordered the game, you will get your extras at that time.