Firstly, and it's honestly a minor issue, I think your question will draw more answers if it had a title that at least mentions the crux of the question, that is "what is a western style room/home?".
Anyway, answering the question, the distinction of a western-style room, home, hotel, bathroom, suit, or even envelopes is a description generally used only in contrast to the "global norms" that are Western-world designs. So far as I can tell, this isn't (usually) rooted in any sort of bias against the non-Western world, but rather a helpful if coarse indicator about what things will look like.
To that end, classification as western style is mostly going to appear in places where that is not the norm or is not endemic to the given place. Japan is a good example as the island nation continues to have its own designs that remain popular, while having imported a great number of western ideas since the Meiji Restoration in the mid 1800s.
Whereas the distinction as western design isn't very useful when all relevant design options already stem from western approaches. Take for example the slender and tall townhomes common in the Netherlands. If such a townhome were constructed in San Francisco, calling it a western design is terribly unhelpful, as a standard townhouse in San Francisco would already be of American (and thus western) design. Rather, that home would be described as "Dutch style", to contrast against the standards found in SW America, which hews closely with standard American construction but with notable Spanish influence, such as tile roofs and verandas.
The distinction also doesn't help when comparing forms that most wouldn't even find comparable. So an alpine cabin (a cold weather, western design) is not comparable to an Alaskan Indigenous igloo despite both being a home or dwelling. There must be at least some similarity before drawing the destination of western or eastern or whatever design.