They are probably downsizing a bit. A little random checking on for sales houses on Redfin gives me the impression that someone with maybe a 2300 sq ft house in San Antonio could get maybe a 1500-1700 sq ft house for about the same price in the the central valley in California (e.g., in Modesto, Merced, or Fresno).
My guess is that it is mostly people who are not living in major cities in Texas moving to not major cities in California.
> If over 65, you can defer paying property taxes indefinitely for a 5% yearly interest rate as long as you don't move. You still owe the taxes, but they'll be taken out of your estate.
"Taken out of your estate" suggests they take the taxes when you die. If you move before you die to you have to pay when you move, or does it still come out of your estate when you eventually die?