I actually think that one is a legit question.
I don't remember if I said this earlier, but I think pretty much any question like this Rosewater asks is connected to
something real, but the part that varies is where in the pipeline it is. When he's asking "how would you like another return block" right after Scars it's making sure people are gonna feel good about the block they already planned, but there's other questions about stuff like evergreen and returning mechanics, printing planeswalkers in supplemental sets, etc. that turn up at the point they're probably just starting to consider the idea.
With block themes or concepts specifically, they plan so far out (the last time Rosewater mentioned it, they had the next 10 penciled in) that when they start to pencil in "Japanese-themed block" for a slot five years down the line, questions like this could be one source of feedback to shape how they approach it when they get there.
I think you have to ditch a toooon of the creative. But setting it millenia in the future helps with that.
There's a few things you can keep. Moonfolk are okay.
I feel Kamigawa is such a great setting because it's so genuine. The setting takes its source material seriously while still creating its own ideas.
Eh. Kamigawa is right at the tail end of Magic's creative nadir. At that point the setting design strategy for new blocks was "And
these people live under the blue sun, and
these people live under the red sun, and..." Everything's artificially split into five overly-symmetrical groups and there's no room for interesting variations. In Kamigawa it's even worse because of the spirits -- like half the creatures in each set had to be spirits, which used up the room for interesting one-shot card concepts and meant that most of the creatures were these indistinguishable abstract messes. It's cool that they used some real elements but the result really is not a success.
If Kamigawa (or another Japanese world) comes back, Ninjas better stay. Ninjas are inherently awesome and always will be as long as the execution is on point (i.e. not Naruto)
The ninjitsu mechanic is one of the more popular things from Kamigawa and Rosewater's said they regretted saving ninjas for the second set when they're one of the primary things people wanted. They're definitely something we'd see again.
I will say that it really bugs me that Samurai and Ninja are creature types. A samurai is a knight or warrior, a ninja is a rogue. I don't like that Knight Exemplar is racist against Asians!
