According to this dev post, Blizzard plans on deleting the beta stats from everyone’s profile.
Why? Those stats aren’t hurting anybody, they’re a game mode that happened and I want to be able to view my personal progress from it. I use my career stats to track my evolution learning certain heroes, and I see no reason why a chunk of our careers should just be deleted. Hell, they even keep stats for throwaway arcade game modes like Mystery Heroes, the RQB stats are absolutely worth keeping.