No idea.
Maybe the Live Action movie is getting a North American release, but they think it too needs to have the "Star Blazers" name.
Or maybe someone sold one of those scripts after all these years (hopefully not the Space Battleship Arizona one someone tried to sell to Disney).
On another note: DHL seems to be really fast this time around and should be delivering Chapter 6 tomorrow instead of Monday. So I'll technically have the episodes on release day.
Also there is this image of Desler's new ship for Chapter 7 floating around from the facebook pages (source unknown to me at present)