The producers likely have distribution agreements on a by-country basis. So, for example WB cannot distribute <movie> in Germany because GEMA has the rights. But GEMA didn't buy the rights for the English subtitles. I imagine technically WB could then sell subtitles rights for <movie> in Germany but it would be a pain because maybe those subtitles were done by <subcompany> for licence in America and Oceania... etc.