I'm not denying evidence for Blue Mage, only that the evidence being reached for is weak and unsubstantial in comparison, especially in comparison to Samurai.
I disagree that the evidence is weak and unsubstantial. There are two interviews which he talks directly about the T-Shirt. In both he mentions webs and webbings. The only job in the Final Fantasy series that actually uses webs in any shape or form is Blue Mage. This doesn't mean that Samurai won't happen in Stormblood, but it does mean that the T-Shirt references Blue Mage, not Samurai.