They originally announced it would be a helm enchant, so the fact it's datamined as a Meta gem doesn't really sit with me. The released stats and proc from each of them sounds like a helm enchant the more you read them. Obviously I can't confirm, but I'm about 85% sure those will be enchants, or as earlier put, an "extra" meta.
I'll have to run some figures once that data is loaded into Simcraft to test the ICD of the 324 Crit + 30% haste for 10 seconds proc versus the 324 Int + no mana cost proc. Crit is pretty powerful for Destruction and Demonology, but not to the point that 324 rating will make the difference. Intellect is still more powerful. Affliction wouldn't benefit from the no mana cost much, but it would be huge for Destruction. Having a non-Backdrafted Incinerate cost no mana would be pretty huge for allowing less Haste and more Mastery/Crit.
Zagam - <Death and Taxes>
US-Mal'Ganis 16/17M T17; 13/13H T18