What does "Wakanda" actually do?
As Replicate is just the Marvel Munchkin version of the Mate card, if you take a look at the FAQ (search for 'is Mate an enhancement card') you'll see that it works like a Wandering Monster card and adds an additional monster.

This means that the Wakanda dungeon prevents players from playing either a  Wandering Monster or Replicate (or Mate if you're playing with non-marvel as well).