I think you guys really need to go back and actually read what the blue says.
"This system is going to launch with fairly conservative rules, so that we can get it up and running as soon as possible and make fun improvements down the road. It’s not beyond the realm of possibility that we’ll eventually allow transmogrification to use the twill set or [insert your favorite item here], but probably not for the initial launch of the feature."
This means that legendaries will not be available at the start of the release so they can get it out quickly, but will possibly be available further down the line.