What’s funny is that, unless the population figures had magically changed drastically in just 2 months’ time, then the population split was close to equal at the start of AV too. Yet Horde were the ones with much longer queue times after the first few days.
One major difference there was Horde having rampaged on most realms and traumatized the Alliance in the WPvP phase which is why Blizzard rolled out BGs early to alleviate the situation, and the interest in PvP was clearly different from the start.