Not really. It seems like they're from Asia and given that Asia and the US have the same region that means despite region lock they can be played in both. At least that's what a little research did for me.
I guess if you want to be extra sure you'd ask around on the forums. Specifically Previous Generations since it is about the 3DS games.
Ultra Guardian member.. if you want to change your username to "Ultra Guardian DJ James", than go for it! :D. Changing usernames is fun and there's also an opportunity to change it back too later in the season.
I see! Well, it depends. If you want advice for competitive sets then you'd open up a thread in there. If you want advise for a regular ingame set then you can ask in Previous Generations (if it's from an older game) or if it's from SwSh then you'd ask in there.
There aren't any general Q&A threads so making your own one if you have a question is the best way to go about it. ^^