Why do some folks think new 767s would allow polaris to speed up. I guarantee at minimum a 24 month lead time for restart of the pax line including spool up of boeing suppliers. A decision for new 767s will only delay polaris and give UA another excuse, but its not like UA was hitting retrofit targets anyway.
What boeing should have done years ago was complete the backbone designs in the concept 787-3 and not ask customers if they wanted it but told them we have this ready to go. Fast forward to today and guess what...airlines want a similar aircraft to then 787-3 just now called 797 and coming in the mid 2020s...go figure