So your examples are a political faction that disappeared in the 1700s and a train in New Zealand?
Why would either of those things be bitter?
Even if you want to talk about Georgia vs. Georgia, the US state is almost 3x the size (in population) and the nation was "Republic of Georgia" as recently as the 90's.
Further, 60% of native English speakers are in the US and also this is the exact headline used by a website for/by US Southerners.
Should the headline have been, "Georgia, the state in the United States, has a coastline?"
Is this really a harmful or inexcusable example of US-centrism? Should publishers in the country of Georgia always explain that they're referring to the country and not the US state?