There really is no value for Delta to purchase any Boeing aircraft going forward. The discussion is probably moot. I would look at the A225, A321XLR, and A350neo as the next purchases by 2025. Further boosting the maintenance relationship with Airbus should also be a major priority. Dump the CRJ 200s, 767s, 717s, 757s, 777s, all MDs, and some 73 7/8s.