The main advantage the wasp had was a superior
BS which is of course now gone; add in Battle Focus and a ++ and the war walker has the wasp outclassed hands-down
IMO, even with its movement rules. You could still run both of course in a codex army as wasps are
FA, which could be fun
Remember that they're only Troops in a Corsair army.
Edit - also if you use them in a codex army they don't use the corsair profile so only have
BS 3.