If you check todays post on PokeBeach, it is clear that Latias WILL NOT STOP DUSTOX EX!!! I say this because everybody is so excited about it. Sorry to get you hopes down.
Yeh, that was revealed when the Latios scan was put up about 5 days ago. I'm not too surprised at it though since it just leaves Dustox more open for play. Someone just forgot to translate the part which was 'excluding pokemon ex'... I dont know how you can miss that out.