I think this may be beyond the scope of TubeBuddy, but as an idea on it’s on, I like it.
I actually don’t understand why google wouldn’t automatically translate all English into the viewer’s native language. I sometimes will find my way to Japanese sites thanks to Pokemon Go and the browser will automatically translate it into English.
Translating your title and description manually however, will mean you’re isolating all other languages of other visitors to your play list.
Until translation is automated via the web browser on the user end, I don’t see this becoming a thing.