My guess is that they have cables on the outside _and_ inside, and putting yet another cover over the outside cables would mean more mass. As-is, they only have to worry about wind and sand, so extra metal shielding is probably not necessary.
Not sure what braiding entails, but according to TFA, they would not have used zip ties. And if by braiding you mean twisted, shielded pairs, then I'm sure they used that.
