I like the idea of using relays to segregate types of content. When I talk to Bitcoin people I write in English, I expected everybody to talk in English in that universe. To other groups of people and interest I use other languages.
Discussion
"I speak Spanish to God, Italian to woman, French to men, and German to my horses" Charles V
I also like this idea, it promotes independent and decentralized groups.
long term this is kinda how I envision the language param tag being used. based on the new relay list nip you could add criteria that automatically only posts to certain relays by the language that is used.
I don't think that kind of automatization will go a long way. It is probably simpler for the client to categorize relays in named groups -- or have some magic algorithm that cluster together relays that seem to be related to some groups.