That being said, I live in a pretty population dense area and my largest cost by far is dedicated home office space. It would be nice for my company to pay for that but it would have also been nice for them to pay for gas for my commute when I had one.
I think CA is likely overplaying their hand. They are not the place of choice for many remote employees (because of taxes) and are trying hard to not be the place of choice for remote companies.