Not sure if this problem was already addressed, but here are some thoughts of mine:
The problem: Im on a german dominated server (Asta) and the chat is mainly spammed in german language. Many people complaining about that, others complain about the fact that they complain at all, stating that the server is german. This may lead to people leaving the server and people from different countries arent able to play with each other… I dont know if the issue is also present on other servers, but i guess that it is most likely the case.
My suggestion: It would be nice to choose a specific chat realm, based on the language you want to speak or a chat filter to hide specific languages in the chat (in that case people would need to change their chat settings to a specific language and they are just allowed to write that language at all). Not sure how difficult it is to implement but shouldnt be that hard at all?!
The outcome: Anyone would just see the language the person wants to see and many heated debates filling the chat would disappear. People from all over europe could play on a nationality dominated server without feeling disappointed all the time.