Ive seen this lens advertised for Pentax on a number of online stores, but I guess nobody is actually buying it, otherwise we would have known if it exists or not
I have seen the version for Canon in a store, though. Looks pretty interesting. Would be great if someone went to the source and asked Samyang if this is even being produced or not.
Some said that it won't be made because Pentax has no FF, some said it won't be made because the little ridge under the onboard flash sticks out too much for the shift (this was specifically said about the K-30, which was the latest Pentax camera when the 24mm T/S was announced, since then we have seen the K-50 and K-3, so I'm not sure this is a valid argument).
The more realistic reason I see is that there isn't enough demand for it to justify production. The T/S lenses are quite hard to use and very specialized, so I assume people who wanted one would just buy a system that already has these lenses available. Its not exactly a lens that you just snap up spontaneously.