It is not a wise decision to spoil such a great product with a nonsense omission. These are the best documentaries available regarding the WWII, to my knowledge. They are not the typical "winner-side" version, even though created by the BBC.
But it is unforgivable not to release it with subtitles, at least, in english. I wonder where were the "minds" behind that rationale.
In short: burn or give it away the stock without subtitles, invest just a little in adding the subtitles and release a worthy edition. You will sell lots of them, worldwide. I am a Spaniard, by the way.