Croatian, Danish, English, Norwegian, Slovenian, Swedish, or Thai ...... other nations are discriminated against..
Why Slovenian? Slovenian language speak 2,5M people..
Czech and Slovak peoples Speak 15M people..
I don't understand it
All the available languages, the ones that you mentioned are languages spoken on the servers that have been merged into the .net server.
So what happens when a server is merged is that the player bases are merged.
So in this case, the Croatian players, have started playing on the .net server and the same goes on for all other languages, except English of course, which is the original and default language on the International server.
Regarding the Czech and Slovakian languages, why are they not listed on the language selector setting is because there are active servers for the players from these countries and usually players from these countries play on the specific language based markets. Of course, they are welcomed to play here also, but by doing so they will have to play using one of the languages we as a market support.
Hopefully this can answer your question why there are no Czech and Slovakian language options available.