Regardless of any shiny lock.. there will be shiny versions.. the same way how people have shiny previous gen legendaries.. regardless if GameFreak has a Shiny Lock, it doesn't stop indivduals from just creating/generating a Shiny Legendary.. Which is why we have Shiny Latis, Shiny Keldeos, Shiny Shaymins, Shiny mews, etc.
Apparently the same websites that offer GTS uploading services to B/W, state that they will add Gen 6 support in a ~month. and wont be long for pokegen to get a update to create hacked/generated gen 6 pokemon.. they've already started initial work on it and revealed that gen 6 will use .pkx files instead of .pkm (since info is different) and have made available examples that they made and also showed a screenshot of one that they created: