Remember when Namco Bandai (or was it Bandai Namco) changed their name? Well Tecmo Koei is doing the same thing, as their European branch is changing their title to -- wait for it -- Koei Tecmo Europe. For years it was known as "TK," which led to lots of use of the #TK hashtag, but now it's KT.
It's unknown whether or not this will be happening worldwide (it likely will be), but it's a thing. If you're confused as to why this is happening, it's because the companies are known by a certain name combination in Japan (the "new" ones like you see here), and they just wanted to make it uniform across the board.
Tecmo Koei Europe [Twitter]