I feel compelled to take to the forums usually to criticize BB for their huge ineptitude at times, however this time in the interests of fairness I feel compelled to post approval of this barracks week idea.
The event is clearly designed as a real world test, to see what would happen if everyone was allowed a level 6 barracks (hence the 10% faster), so that BB can measure the impact on the game.
Introducing such a small change in order to measure real-world impact, is not actually the worst idea BB have ever had, and clearly they have taken some feedback that test server runs are in some (but not all cases) pointless.
At least from me, well done BB
Lets hope it all goes well.