My theory is WotC will want to use names (for PC species) only linked with English language to can be used in the rest of settings, and to avoid some report about cultural apropiation. Then the future hengeyokai will be the "skinwalkers" or like this.
The lore or background of the PC species should be easy to be changed. Something could be true in a world/wildspace but in other to be different. Of course WotC worry about the feedback when new PC species are showed in the UA playtest.
The fun fact is Western players are interested into a Japanese D&D, but Japanases would rather fantasy based in Western culture because this is "exotic". How explain it? For an Italian a Irish or a German the cowboys movies are "exotic", but for an American living in California or Texas is not at all.
Other point is Japaneses are too used to certain tropes showed in the isekai, for example an holographic interactive screen showing "game stats". If it was a character from Kamigawa: Neon Dinasty this could be explained, but it is too "metagame", breaking the spirit of the story.
And this is worse then the main character is "broken", he doesn't start from zero to zero, but OP, overpowered.
You can love those funny characters, but after the final boss is defeated and the world saved, then this becomes "boring". The TTRPG settings are designed to happen a lot of facts in different places, without links between these.
* WotC has hired some Japanese artists for Magic: the Gathering.
* In my opinion a "D&D isekai/jidaigeki" should show new elements, not only for D&D players but also for otaku* community. (I hope "otaku" be allowed because here it isn't a pejorative term). If there are plans for future new classes (psionic manifesters, ki martial adepts or incarnum soulmelders) a "jidaigeki" setting could be the right place. And what about a cultivator class based in xianxia fiction?
* I imagine the spirit folk like a mixture of elves and halflings, something like shorter elves with a light shota or loli touch, kindred of lung (Asian dragons) ancestors.
Varana are right to roleplay the funny foreigner, friendly but unwittingly rude because he doesn't know or follow the courtesy rules.
The "nezumi" (ratfolk) will be renamed "tari" (an updated version of the rat humanoids from Dark Sun).
Half-oni as PC specie? Or like a goliath subrace.
Yuan-ti could be "good people" in a jianhgu setting.
The korobokuru shouldn't be only reskinned dwarves. Will they be a subrace? Their culture could be based in no-Yamato/no-Han communities, but let's take care about possible pejorative stereotipes.
