"I did some reading up on this lately, and I believe Sabersite said that as long as they don't have a static PID (This applys to 3rd Gen as well), that they can be shiny.
Static PID = Either can't be shiny (Restricted to one Nature, one set of IV's), or if the PID corresponds to a Shiny, then it must always be shiny (Example being the Shiny Zigzagoon)
Dynamic PID = Has the potential to be Shiny, because it's PID is randomized when you recieve it, along with it's IV's, and Nature (Example is soft resetting at the green man in a Pokemart)
As far as I read, Sabersite concluded that all 10 ANNIV's and their variants had Dynamic PIDs, and therefore can potentially be shiny.
So, as far as I am concerned, anyone telling you that they can't be is lying, either out of idiocy, ignorance, and/or jealous."
So this is false then? I have to get a refund from 2 people :|