It seems whatever may be going on with out-migration from San Diego will be eclipsed by in-migration.
Per the article below concerning various apartment projects, not to mention countless other new home, condo and apartment builds in PQ, Poway, Sorrento Mesa, etc., etc. it appears that we need to build 17,000 units PER YEAR, just to keep up with demand, and we are no where near that number. Also, don’t forget many of the thousands of apartment dwellers aspire to be homeowners one day.
The rest of CA wrt housing may tell a different story, but, from a real estate perspective, San Diego seems to be looking good well into the future.