For clarification: Delta announced SAN-Hawaii, but never flew that route (western excepted). Just guessing, but DL realized they couldn't make money and abandoned the route before the first flight. AS promptly filled in (I'm sure DL colluded, but that's speculation, because collusion would be illegal). Most likely, AS is making money.
900er's are speculated to not be etops. Most likely will fill in on slot controlled routes. Perhaps EWR, BOS or DCA.
Route swaps are speculation at best. We've flown one to two flight to MEX, GDL and PVR for the better part of a decade. We also used to fly LAX-CUN, but apparently DL can do it better.
What can be said about "our alliance" is that there is a lot collusion. If you truly want an end to it, you would have to force a merger. Do the unions have that much power...