Originally Posted by
NPI
I disagree with OP. His concerns are theoretical only. Evocation has a 1:30 CD, you can't burn for 90 seconds without going OOM, especially not using only ABs. Especially not when ABs seems extremely overpriced (at least in the blog post), so 4 AB(4) s will take you from 100% to 0%.
Actually this concept is the modification of the Cata mage, which had the adept mastery, but intellect also gave us mana. That was a problem, because it gave only max mana, so if a trinket or a weapon enchant procc'd, your mana% went down. In Legion, if we will have a mastery enchant proc, it won't matter anymore.
This means mana will be a real resource, you can just change your rotation if something really needs to die, without punishing your dps afterwards.