Who cares. Not significant if 1000-2000-3000 people get laid off from one company.
Want to see something that accelerates a southern CA decline? Cut in defense spending. I think a lot of the real estate implosion in SoCal back in the late 80ies resulted from a defense budget cut. I remember living through that when friends parents neighbors were being laid off left and right.
Some of my colleagues working at BAE, Northrop, Raytheon, etc here and SD are sort of nervous. Aside from pension under funding, a lot of them are depending on gov contracts that have yet to be realized.
Side note, nost new hires no longer have a pension option.