You're right he didn't say it was a healer, I am mistaken. However, SE decided GNB should be a tank because there are 3 tanks and 4 melee DPS. Conversely, if that's the case, it would also make sense that because there are 3 healers and 5 ranged DPS, the second new job would be a healer. Also, we just got 2 DPS last Expansion.