WikiTree uses the Family Search locations list, that's what you will see on the location drop down.
But, thousands of the FS locations are incorrect, using made up locations such as British North America. Which as a location never existed.
Lots of confused and mistranscribed locations, as an example the town of Simcoe in southern Ontario Canada and the county of Simcoe which is 250km north of the town.
A place called Home Township north of Lake Superior in Ontario confused with the Home District which was in the south of Ontario, they are almost 900km apart. Home District was settled in the late 1700s and early 1800s, Home Township was not settled until many years later.
There is no requirement to use the drop down list.
Many projects have lists of correct name locations for various time periods.
What places are you looking for?