I see no reason why haste would gain so much and I believe that this will be chalked up to a bug in his spreadsheet.
Haste, if not able to hit the 3 sec cs, will only affect Censure ticks and auto attacks. More auto attacks will bring a slightly increased number of Art of War procs and the few additional SoC hits though, but I do not believe that this will be enough to increase its value over mastery which is such a large amount of our damage at the moment (for me it can be over 50% depending on the fight). I have to fall in line with those that agree that haste is not and will not be our most valued stat until the 3 sec cs is obtainable.