"This is not easily doable right now because the Hive API does not expose the language of a post as a top level value."

I was thinking about that. It would be a challenge to make another algorithm to sort posts based on metadata if implemented outside Hive API using json_metadata from posts to announce the language.

"Also not sure we have the required volume of posts/snaps to actually make it doable. I fear too many languages will have just a handful of posts per day."

That's why the whole system would not be meant to restrict but to prioritize posts on user's feeds, where posts in the user's preferred language(s) would appear first.

That is just a suggestion to make the environment friendlier to common people to push into engage more with Hive posts. Most people I know don't understand English and it's being quite challenging to promote Hive to them.

But those are just my opinions and suggestions.