Batwing closes in high winds (but when I say High Wind...it's got to be pretty damn high to shut batwing down)
Superman does actually have a wind detector and prior to each launch the system weighs the train and takes into account the wind speed the best it can to optimise the launch however in very strong winds the ride will cease operations. I know that the Giant Drop at Dreamworld is capable of operating in winds up to 120kph and dreamworld even had it on their website at one point a few years ago but weather or not they still do operate in winds that strong is a different story.
Basically when they say "High Wind can effect operation" it pretty much means it has to be a pretty big ass storm to shut it down. In the end the final call comes to the park supervisor to cease operations of certain attractions until the adverse weather conditions stop.
Also what Nitromefan said about Batwing's cable is essentially correct and the cable is unable to be protected from the elements like the Intamin Giant Drops using the procedures stated. This is also why at night time the Giant Drop's catch cars are kept at the top of the tower.