Hm, I don't really see how useful this would be if there are multiple posts in different language associated with a particular post in english. Then, you basically have redundant posts appearing

"Then, you basically have redundant posts appearing " yes thats exactly why you have this option also to sort this option i f you would like to see this post and other post in another language than just post in a specific langauge that is controlled by site/browser.

And then site owners can decided which post should be "redundant" translated to different languages or not.

If a user speaks one language ie spanish but also would like to see the languages in the site that is in English he can do a tickbox to see the posts in both spanish a n d english so he doesnt miss any blogposts that is just written in another language and dont appear in the other one..

hope that explains...