It hasnt been mentionned in patch notes, since it was more or less something that was broken, and watching Yoshi-P playing his BLM on extreme Titan i noticed that :

MP regen Tick is now SYNCED, that means , the tick gonna kick in every 3 sec after entering Umbral mode

before you could manage to get the tick just after bliz 3, so its a loss of 1.5sec average on every cycle

Double flare now impossible, fire 1 following bliz III> fire III > will be casted on normal speed, so its another 0.5 sec

Im not crying nerf cause i find it better that way , and its how SE has designed it

But just for people to know, i predict BLM will have a 5-10% overall dmg nerf

i parse 310 dps on lv 50 dummy, i think i gonna do down to 290 dps now, i will update with the new parse next week