Czech Republic -> Czechia
In April of 2016, the country of Czech Republic shortened its name to Czechia. This was mostly because they wanted to be able to market the country to the rest of the world through sports and sponsorships. The conversation about shortening the name began 20 years prior, and in 2016 they eventually agreed on Czechia as it’s easy to pronounce in each of the country’s 6 official languages. While OFFICIALLY the country will still be known as Czech Republic, Czechia is now the official shortened name of the country.
https://en.wikipedia.org/wiki/Netherlands
#1 also in Germany we still call it "Holland", this name was never really taken away from them.
#4 well, the more important thing that happened was 1993 when Czechoslovakia separated into Czechia and Slovakia.
Too many times, incorrect names are applied to places for the sake of a foreigner's convenience. eg Munich and Cologne are not the names of the places.....