I'd love a worlds there, but I think the issue isn't that UWW doesn't want to go to these places but that these places don't want to host worlds. From what I understand you need to bid and they simply are not interested, which is why it ends up being the same 4 European countries and the occasional central Asian one. I feel like Budapest has hosted like half of the past 10 world championships, lol.
Hats off to Japan, they are awesome. I am sure they have far fewer total wrestlers than the likes of Iran, America and Russia. Add in Judo and Sumo taking a lot of the talent and it makes what they have accomplished all the more impressive.