https://www.pcgamer.com/mortal-kombat-11-will-have-microtransactions-for-cosmetics/

Mortal Kombat 11 will have microtransactions for cosmetic items such as skins, gear, intro animations and victory animations, developer NetherRealm Studios has confirmed. 

In a livestream yesterday, NetherRealm said players will be able to purchase time crystals with real money, and then use those crystals to unlock cosmetics. Players will also be able to spend crystals on "easy fatalities", which simplify the button inputs for the series' trademark finishers. You could also spend real money on easy fatalities in Mortal Kombat 10.