it is only a simulated game and such a map would not trigger any reaction from the Chinese or even the counterparts.
on the contrary, I think the Chinese community would be happy to play in a simulated map of their Chinese territory, and their counterparts would also be happy.
If you think a nation could get offended and have negative reactions at this point no DCS map would be possible to design.
Korea could also be offended by seeing its North Korean counterpart unleash an invasion.