From what I can see the only real change is that we get Reward Cards instead of Booster Packs. Everything else is similar. People could still reward farm as usual. the difference would be  them getting rewarded out of 10 cards. Alpha and Beta markets will do well. But if reward farming is a widespread thing, you've just kicked the can down the road. 

Maybe you should play around with the idea of some tournaments or quest system to reward dedicated players. But I do think things will be fine for a time.