Metal Gear Survive ... uhm, no, just no. Guess I say myself every MGS after TPP isnt canon if something like this comes out. we dont need a L4D-clone in MGS universum, like really? WTF?
Launch a missile filled with the zombie virus in it? Zombie's usually aren't that smart...Unless you mean they want to Zombify the Metal Gear, in which case...WHAT, It's a machine, how? XD