Even though it is simple to change the server you're brought into, there's no reason to not allow players to choose which region they'd like to connect to by default. Having the game throw you in to whatever it thinks is best, especially when players can have significantly worse connections to different servers, it just ends up being an annoying chore to have to check every time to see if you're in a server that gives you 3x your ping or more.
Think of how trade market allows you to select your default level filter, where you can just Shift + RMB in order to lock your default level filter to the selected one. This would be functionally identical and would just allow players to have more freedom of choice that is otherwise not given to them.
For the record, in the picture below it's shown that my recommended region is EU but I am an NA player.