Sure, Matsuno's contributions were exposition-heavy, but they added so much to the worldbuilding of XIV in fleshing out the IVth Legion and basically the entirety of southeastern Ilsabard and western Orthard. The non-lore story and character writing was nothing spectacular, but competent enough to be on par with the writing of other side quest and not stand out negatively. And concepts like the Field Notes I would absolutely love for the developers to also carry over to other content. While it is just an exposition dump, it is a great way to supplement information that's usually reserved for the Encyclopedias into the actual game.
Overall, I think his contribution has been a net positive for the game and as I was very much looking forward to the Dalmascan liberation they hinted at at the end of Bozja as involving the Warrior of Light. I will miss Matsuno's work for XIV.
Also, what a dark timeline to live in where Matsuno moves on from XIV without any fanfare and farewell, while Yoko Taro who gave us some of the worst writing in XIV in years is invited on for the next Live Letter.