If Dark Justice wasn't written by John Wagner I would suspect it was intentionally written as a strong treatment of how to do a movie sequel:
1) It re-locates the action to a sci-fi location (the Virgin Atlantic) that can still use real places (corn field, soccer stadium)
2) It brings Anderson and Dredd back together and throws in a small additional team
3) It plays to dark visual effects being cheaper and hides Death
But it is written by John, and having met the chap I'm 100% sure it was not his intention.
Still you can wish - and it would be pretty easy to explain in an inter-stellar dimensional accident how the Dark Judges were created.
Hell that makes sense to me. T'would be a mighty Movie -and cheap too! But alas I fear any celluloid story of Judge Dredd and Mega City 1 won't be seen again for a long, long time. :(
It's not happening. Let it go.