I mention this only because the originally quiz was from 2010. Many users have created similar quizzes over the years and I don't want to be accused of stealing their idea.
How about Tanganyika?
Burkina Faso was Upper Volta
Nigeria was Sokoto
Vietnam was Dai Nam
Cambodia was Kampuchea
North/South Korea was Joseon
In case you would want to add these so you have a more complete quiz
Welp, learn something new everyday
I don't think I've ever heard that Australia was formerly known as New Holland, though.