Interesting theory, though I don't think the Reddit Genshin crowd would take it well.

I think what I've noticed in Hoyoverse games isn't the presence of any explicit ML themes, but rather the absence of explicitly liberal ones. That's the one distinctive facet of their storytelling that often leaves the impression that there's something different between their themes and Western media tropes.

The most plain example of this isn't in Genshin, but in Honkai Star Rail. There's a moment in the first planet of the game where the land is near collapse from environmental disaster, on the brink of civil war due to an apartheid regime and badly demoralized about the future. The authority figure, who is ideologically compromised to put it mildly, is deposed and the new leader decides to refrain from publicly broadcasting how compromised the previous government has been. They choose to do this because it would badly shake confidence in the planetary leadership and because knowing that the past authority purposefully exacerbated the world's class segregation would inflame tensions towards civil war. Revealing to the public the nature of the past leadership would do nothing but harm at a critical moment, especially when the planet was finally offered an opportunity to rebuild by resolving the environmental crisis.

Let's just say the Reddit crowd did not take this well. One of the hallmarks of liberal storytelling is the importance on individualist moral purity towards core liberal values. The ultimate deontological anti-utilitarian mentality. In a context like HSR's, you are meant to tell the truth, no matter how destructive it might be, and damn the consequences. The liberal mindset loves to bash utilitarian "end justifies the means" decision making, but their "means justifies the end" reverse calculus is far more destructive. Walking away from a fire you gave the spark to is worth the moral absolution of having stuck to your "principles."

In other words, although the surface rationale for this principle is "democratic accountability to the collective," the result of valuing the means over the end means that the true intent is that individual self-gratification is more important than the collective common good. Wthholding the "truth" from their perspective is a massive sin, and the idea that someone could commit a sin for the sake of the betterment of the community is completely anathema to the liberal worldview. There are stories like that of HSR's dilemma in liberal Hollywood and Video game storytelling, but it is always baked in a overarching thematic emphasis that what the character did is wrong or at best, indicate to the audience through a whole song and dance that the story is self-indulgently bathing itself in "grey," "complicated" themes. HSR simply has the leader character make the decision in an aside and then the story moves on. The player character gets to make a dialogue choice to blurt out "a lie is always a lie" HBO Chernobyl-style liberal outburst, but it's a comestic line and the leader ignores the player's input. This is not their decision to make.

The story was flamed on Reddit for revealing Hoyo's Communist roots to detractors on one end and with the most favourable interpretation being that the government forced Hoyo to insert "pro-authoritarian" propaganda themes in the story. They can't fathom the idea that "leaders withholding societally damaging information" is a fact of human governance rather than a trait of the West's designated adversaries. The West simply puts a bow on it and calls it "classified information" or "national security" to dodge their surface claims of "democratic accountability." They always mentally masturbate to their fantasy of the Soviets not fully disclosing about Chernobyl and never reflect on how they were led by the nose to the Iraq War by an administration that openly lied about WMDs, by consecutive governments that openly sponsored programs like MKUltra, by endless lies from their leadership ranging from the Vietnam War Gulf of Tonkin false flag to the Nicaraguan Contra war crimes. None of those crimes by their own leadership was ever punished and yet the liberal theme that "the truth will always come out and lies will never last" is still odiously and hypocritcally pervasive.

This is what I've noticed that Hoyoverse's storytelling has. Not a presence of leftist themes but an absence of liberal ones.