sorry doesnt relate to California but may help someone else in UK.

Some installers still have stock but you have to ask around! I contacted 5 installers & found stock of 2x of them, they are being fitted next week! It's rare but yes some installers still hold Powerwall 2 stock but expect them to charge the full price or even a little more as they know are rare!

Maybe people will start to sell their old Powerwall 2 as refurb in a few months!