Where they are from, tells them where the players live, and that also tells them the languages spoken.
Some people speak more than one language, so if you ask them to check a box for languages spoken, you would get that info, but have no idea what their native language is.
In the US, you have a mix of languages being spoken by different people, but the native language is English. The people living in the US have to learn English to get by on a daily basis. The same goes for other countries. So you get the most important question answered when you ask where they live because that tells you the language they can speak and in most cases, the person responding would be telling you their native language with that answer.
There could very well be some very minor marketing in that survey, but without your email, you will never notice any of it, because they can't send it to you.