Does ChatGPT properly handle western social customs? I'd say yes, and I presume that's because it has a truckload of data involving such customs and even some that explicitly talks about those customs. People do stuff, it gets recorded, then into the LLM.
In this case though we are talking about "artificially" generating content such that the LLM responds how the group making the content wants. Maybe that's something that was already done and I don't really have any ground to stand on?