If the concern is in giving offense to Asian audiences, why not just change Cantha’s architecture/culture? This breakaway from the melting pot of Asian influences would give a wonderful opportunity for new storytelling, and would likely appease those who felt their culture was unfairly represented in the first game.
Cantha could now be a hostile, xenophobic dystopia (which is where the story seemed to be going), or maybe the culture of kaineg city will have become so metropolitan and modern to have supplanted and marginalized old cantha. Or perhaps Luxon/Kurzik influence reshaped the continent.
My point is, I’d be willing to pay good money for a Canthan expansion, and i think that this gives Anet a unique storytelling opportunity.