Originally Posted by Steward
Well, female characters wouldn't have to pay the feat tax, which might encourage that.
In addition to this (which is true), the key word in that sentence is 'chosen'. It's quite possible to approach the Voidblades and petition for training (or, rather, to hunt down a Voidblade and ask her to train you), but there is a longstanding prejudice against males in their order which means that it's very unlikely for them
to come looking for you
to offer training.
Mostly, it's a fluff thing, and is easily edited out of the class if you don't want it there.