That's an interesting question. The charter just says "one month after it's available to the public" Well, I know plenty of people were able to buy it on Friday, 3/5. So would PHB3 go live on 4/5, the actual 1 month from first release date, or 4/16?
Well.... that's splitting hairs really, it's two weeks difference... as I don't have it, nor do the other judges (that I'm aware of) you can't be reviewed anyways until it's available in the compendium (I forget is it 2nd Tuesday or 1st Tuesday they update?) or the street date for most retailers. (I won't be buying it so I won't be reviewing until the compendium is updated)
Regardless though "the public" should be everyone, a small subset of the population typically wouldn't denote the public... I think it should be when everyone can buy it (the 16th).
That's fine with me, I can't even make another character if I wanted to, so it's no skin off my nose what day it goes live, just something I thought interesting.
The charter is silent on this, since DMs have a lot of leeway in giving out quest XP. That said, I've done my best to promote doubling it, as DM, judge, and when reviewing adventure proposals. Pretty sure some others have beaten that drum as well.
In other words, you certainly CAN award double quest XP, and I encourage you to do so, but you're not required to.