Today’s earnings stated 2020 retirement of some portion of the 763ER and A320 fleets (no specific numbers given).
I suspect the A320s will be replaced by A221s and A223s with no range restrictions on them making them suitable for cross country thin routes.
I suspect the 763ERs will be replaced by 764s for South America and in the short-term we’ll see a reduction in secondary Europe service that allows them to use the 764s and A330s on trunk routes and leave the rest of the traffic to AF and KLM.
Perhaps some of those will see the 752 return (which has been notably absent from retirement discussions). Thinking of a route like RDU - CDG which could revert to the 752 in the short term and become an A359 in the longer term.
DL as much as anyone could use Boeing’s NMA to replace that 200-250 segment but I’m not sure we’ll see one from Boeing in this decade. Perhaps DL will convert some A321 to A321XLR to address this segment?