I don't work for AA, but I don't think this has anything to do with downsizing the operation at SFO in any way. They are merely going to stop basing crews there. From what I hear, this is the first step toward eliminating the smaller domicile stations (in other words, BOS and DCA are on the block next) in favor of getting everyone in to NYC, MIA, DFW, ORD, and LAX ... and STL for the TWA orphans.

If the retirement spike has hit SFO particularly hard, and if closing the smaller bases was on the radar anyway, this makes more long-term sense than paying to move people to SFO to backfill, only to pay (again!) to displace them when the base closed later.