Maybe your experience of XI has been different than mine, but what I got out of it was to never trust anything SE says about their own mechanics at face value. Player testing is ultimately more accurate than anything SE is usually willing to give out. Anything the devs hand the players of XIV is a gift that still ultimately has to be verified anyways.
Also, regarding the idea that people in XI didn't have a good understanding of the damage formula, I would disagree. While it was never completely flushed out down to decimals and rounding error, it was pretty close. I remember participating in a number of theoretical arguments regarding builds that could be conducted completely with math based on community derived formulas. The melee damage formula for XI is clearly spelled out on the BG wiki as well.
The game is still in its infancy and rapidly changing. To expect a full understanding 3 weeks after a major patch is unreasonable in my opinion. This comes down to community driven research. When the game's population ideally rises to a more acceptable level, maybe enough players interested in exploring the formulas will come together and collectively put in the work necessary to figure it out sufficiently. For now, while you may not like the limited information being provided by both devs and players, that may be all the community will have access to for awhile. Considering the game's mechanics are likely to change at least once more in the near future, I think it's reasonable to accept this.