Don't know why y'all are going crazy over this..... aren't you going to have at least one holy power pretty much all the time? And even if you don't just CS and you have one.
Think about how the ret rotation will work at 85, you play CS, X, wait. now consider this happening:
CS -> 3HoPo
TV -> 0 HoPo
CS -> 1 HoPo
If at any time during the CS GCD, TV GCD or the wait you had a HoL proc then you would be unable to use it until after the second CS (assuming no DP HoPo from the TV).
Therefore rather than TV filling the boring "wait" and just pushing the next CS back a little you still have to wait, so mastery helping with the clunky rotation a bit is gone. And more importantly our mastery is RNG and as far as I know has no ICD. There can be 2 auto attacks between two CS's therefore it is possible to lose a potential HoL proc.
I can see why they have done it, it decreases our burst in PvP as we will be less able to string multiple TVs together.
However quite why they have decided to make a bad stat even worse makes no sense.