That doesn't really make any sense. There is no magical deity that arbitrates rules of English. It is merely a tool invented by humans to use as they please. The only semblance of "incorrectness" that might be found is in failing to communicate with the reader, but in this case you clearly had no trouble understanding what "the Ukraine" meant and I suspect nobody else has either.
> and politically
This makes more sense and is a much stronger point, but political correctness is bound to intent. There is no evidence I can see that suggests "the Ukraine" was previously used with intent to offend or marginalize the people of Ukraine. Even if "the Ukraine" can be used as a politically incorrect device, that does not imply that all usage is politically incorrect.
> It’s called Ukraine.
Officially that is true, but there is typically nothing official about a casual comment made on Hacker News. As before, context is significant, and there is nothing in the context that I can see that suggests that the comment was made in some kind of official capacity.