Generally speaking, in-game results of any beta of a game I've come across has NOT carried over into the actual release, and for good reason. If something needs to be tweaked, or an exploit was discovered in beta, it could be fixed, reevaluated, and didn't have an impact on anything else...it's basically a lab setting.
Since any wins/losses from the current Arena beta are carrying over to live, what happens if an exploit is being taken advantage of, or if something is found to be impossible and so causes a guaranteed loss for players?