The Witcher 3: Wild Hunt will indeed have a day one patch, to make the first-time experience as smooth as possible.
Like many modern games, The Witcher 3: Wild Hunt will have its day one patch. According to the developer however, it wasn't born out of necessity.
Miles Tost, level designer at developer CD Projekt RED said in a few recent tweets that the game's day one patch is a result of the team continuing to work on the game even after it went gold.
@DavidMo92898701 We have one, but not because we need it, but because we want it to be the best it can be when it reaches your hands.
— Miles Tost (@MilezZx) May 4, 2015
Tost added that the patch only brings some "minor tweaks" and that the game is good to play "as is."
The Witcher 3: Wild Hunt is out May 19.