Originally Posted by disenchantMINT

The details of the codeshare have not been publicized, however the previous announcements indicated the B6/AA codeshare is limited to BOS/NYC markets. Therefore the B6 RDU route expansions are not "replacing" AA any more than they're "replacing" DL.

And now to opinion: if the past is any indication, AA/DL sharing dominance at RDU may not come back. During the last downturn, AA scaled back significantly at SJU and in the Caribbean. Now B6 has a significant presence there to this day and is by far the largest carrier at SJU.