I don't know when exactly FIFA WC Stadiums stipulations have changed, but I'd bet they've changed since France 1998, considering the tournament also featured a stadium with a capacity less than 40,000. Wind, rain and snow are just as detrimental to a soccer match as extreme heat. We call them that because that's what they are named now. We can cross that bridge in 9 years. Are we not allowed to call it "Allianz Arena?"