I'm not sure what exactly you are reading here. The 2 posts by Matsui are about Magic Accuracy Skill and he does not explain how much Magic Accuracy the Skill is. The Magic Accuracy Skill is almost the same in the table as it is now, with the exception of Lehbrailg +1, where it has a lower skill now than it is written in the table.
Please not this line in the first link
"
*The "magic accuracy +" value listed in the table is the value when "magic accuracy skill +" is converted into "magic accuracy +"
Matsui is explaining back when they changed the layout on weapons to make the hidden stats form ilevel be clear, that these 3 weapons effectivy bonus is X amount of magic accuracy.
if you look up the weapons information now you will se it has the same value as magic accuracy skill
So matsui is saying 203 magic accuracy is what you get from 203 magic accuracy skill
but you have to go look at the weapon to confirm it.
aka it was not as easy to "grab and go" as someone posting oputdated information on bg. when incorrect information is easier to obtain then correct. ppl will run with incorrect information, and i think that is what happened here
Matsuit saying what "magic accuracy" a weapon has
117 Atinian Staff Magic accuracy +203
FFXIAH. bgwiki and ffciclopedisa saying what "magic accuracy SKILL" is on it = 203
203:203 = 1:1
TLD:DR
He is sayin 203 magic accuracy skill = 203 magic accuracy
and its confirmed by the JP testing
---edit ---
Her is matsuits table from his explanation but ive added added with magic accuracy skill from the weapons right next to him saying what magic accuracy it has
... and leaving out an a