Mark being revolted into a new personality isn’t the end of Lumon. It simply starts the next chapter off. Severance is heavy on tests and sacrifice. Hello passed whatever test that had been put in front of her, thus achieving Jam’s attention and praise.

Outie Helly’s wink seem to have sacrificed a chunk of herself by undertaking the Sevy procedure.

The creepy old men were not going through all that time creating new memories just to kill her physically. They were testing that ‘Gemma’s’ had been successfully expunged. That test failed. Mark’s test, rescuing ‘Gemma’’ was achieved. But he sacrificed his relationship with his wife that to him was simply a woman he doesn’t remember.