Yes, Centaurs are in the game. They are “oddities”, which are a special form of trace. You fight them. Other oddities include warewolves, vampires and pixies.
Yes, we’re expecting to see centaurs in the game. Not sure how they will work of if we’ll be able to fight them, but overall, centaurs are expected to make an appearance in WU.
Do note they are not considered to be “beasts” in the Wizarding World.