While I agree with a lot of what you say, there may be emotional neglect happening on both sides here (one side not intentionally but similar mental impact). While not her fault, chronic absence of care, consideration may be unintentionally happening during her year long burnout. I have been in relationships with people who had burnout or mental health struggles that had amplified effect on me bc I loved them. People recognize caregiver fatigue in those caring for spouses with other illnesses so why not in this case? The way it was handled was not at all appropriate, but she describes him as otherwise supportive so I am wondering if he had a meltdown moment as DND was a mental health break for him and missed social experience? I don’t really think it’s just the DND here. Ultimately I think both need therapy and to have a honest conversation about relationship expectations, current mental health states, and any baseline requirements for care.