Fujirumors was the first site to talk about it (thanks to FR-readers who shared the information in the comments and via email)… and, even if there is no official statement about it by Fujifilm, I believe that the information shared with FR is correct: on newer X-T1’s the d-pad buttons are improved.
Go to minute 6 and listen to the beautiful clicking when openbloom presses the d-pad buttons. He is one of those who replaced his X-T1 with a newer one because of the light leak.
“I was comparing the new X-T1 with the one I was returning, and there is a defintite difference between the buttons. Hear that clicking? Now, the other one I had wouldn’t hardly click at all. […] I was fine with the buttons before, and all I can say is that I’m much happier with them the way they are now!”