I dont think something has to be unique to have value, all sentient life has value. SOMA spoilers I dont think theres anything to suggest that the version left under the ocean died before we see the version in the ARK. And they presumably woke up at the same time so those lives were running concurrently. If anything it proves that the suicide cult was wrong- whether or not they kill themselves the copied version will be the same and go on to do the same things it would have done otherwise because its just as much them if they kill themselves or not. But killing themselves makes it a tragedy.
I always find this specific topic of discussion really interesting.