If this is true, that's just straight up fucked for them to make a change like that last minute.
On another note, according to the newest 7.1.5 SimC build, I'm actually going up DPS with this patch.
LIVE EP/DS/AP: 545k
7.1.5 EP/DS/AP: 537k
7.1.5 MP/Vigor/AP: 568k
That's with legendary boots/bracer, at ~886 equip / 892 bag ilvl.