Tamashii shifts its focus from time to time. They're definitely not gonna give up on this line unless it's selling badly in Japan. I don't see that being the case considering everyone is buying from Japan as that's the only place they're allowed to sell them. This line has seen more steam than most other Figuarts lines I've heard of, except kamen rider probably. With no SW, and scheduled figures, they're diverting attention to other lines, reps have spoken about that in interviews, factories etc, they all gotta have the capacity to keep up. Has nothing to do with a line being cancelled. And Even so Tamashii's also brought plenty of stuff back after years.
The only thing I could see is that they're annoyed by their licence limitations and you can thank Disney for that (as far as I know). But really, they're not cancelling this line, I don't think that even for a second.