I honestly don't think this is true. In many places outside the US our devices will default to US spelling, making it appear as if the language spoken by the locals is US English.
But when you look at things like the type of English being taught in school, or the language used by the government, it'll be UK/International English.
I regularly correspond to people from all over the world, India, China, Brazil, France, and they all tend to use US English, thus the suggestion.
Commonwealth countries are relatively minor in population compared to the USA and the rest of the world.
And yes, default US spelling in devices does play a role. See prev. point about technological and cultural dominance.
> Commonwealth countries are relatively minor in population compared to the USA and the rest of the world.
Given India's presence in the Commonwealth, this seems an odd assertion. 2.6 billion people live in the Commonwealth[1].
[1] https://en.wikipedia.org/wiki/Member_states_of_the_Commonwea...
Kinda forgot India is still part of the Commonwealth. Maybe because all Indians I ever corresponded with uniformly used US spelling, likely because they work a lot with the USA. YMMV.