I presented this idea in another thread.
Queue times would be as low as they could be for all players. Horde would no longer complain about the 50% honor bonus (removed). Horde would no longer complain about queues. Alliance would no longer complain about win rates. Premades could be separated into their own queue (much to their dismay). Players would no longer feel like they have an unfair advantage or disadvantage. Players could play both sides of the map. Inequalities in maps could become evident over time and help elicit balancing attempts.
There really are few downsides. Would there be dilution of faction identity in random battlegrounds? Yes, but only minor lay. PvPers are, generally, not heavy into role-playing. Random battlegrounds have no consequence on the playable, non-instanced world. Outside of tuning/balancing changes, Watson Gulch, Arathi Basin, Alterac Valley, etc. are all the same as they were introduced. It’s hard to have loss identity in the battlegrounds when they only changing parts are players.