Just FYI, the official translation for [Letter from the Producer: Part X] was posted this morning with a bit of a different take on Monk buff than Reinheart had translated in real time:
Letter from the Producer: Part X
0:05:48
Q: Please tell us about adjustments planned for jobs other than dragoon.
A: As I mentioned during the previous LIVE letter, there are a lot of cases where melee combos and chains are interrupted making burst DPS difficult, so dragoon and monk will be receiving roughly a 10% increase in damage per second. Rather than reducing the effectiveness of other classes, we will be making adjustments to increase certain elements this time.

Monk's Greased Lightning effect, for example, will be increased. Also, we've noticed that because there are so few damage bonuses for attacking from an enemy's rear, players generally focused on attacking from the side. We'll be increasing bonuses for rear attacks, so if you use monk the way we had intended, your DPS will increase significantly.
So it looks like a ~10% increase in overall DPS is confirmed.