I dont think you guys did much testing or you have crappy testers because you would have seen that the players on Pandemic can just grapple up to a rooftop and the zombies can't get up there and that's game or they place a few barricades and block off a building or hallway and the zombies cant do crap about it. This mode is severely screwed!! Remove the grapples and barricades it ruins the game.
Grapple Guns have always been disabled in Pandemic. If survivors can get somewhere in Pandemic, the infected can get there too. In fact, infected players can jump higher and farther than survivors.
Remember, you can climb on top of an opened door to reach places that you normally can't jump onto from the ground. We've also buffed infected players' resistance to Barricades with today's update, so your chances against survivors have never been stronger as the infected team.