The natural gas plants have been increasing - just not the huge steam plants. Lots of smaller n.g. stuff going in, including a lot of peakers (engine or turbine units; maybe a few fuel cells), and cogeneration at larger industrial sites. And when you were counting the dead nukes you forgot Rancho Seco (which was SMUD, not PG&E or one of the other big utilities) - shut down since shortly after 3-Mile Island's little debacle (and with the same type of reactor as 3-MiIs) and now decomissioned and largely demolished; however, there's a large solar array at the site and a n.g. plant also, making use of the power lines etc. that were built for the nuke. The site has rail access, BTW, not that there's much evidence of modern use.

Then there's "renewables" - which are a Very Big Thing in CA with peak solar now approximating the output of a full-scale nuke (just one of them, of course) and wind etc. helping too. Some older n.g. plants have expanded a bit - like Pittsburg. The only real downsides in what's been happening are that 1) CA is very dependent now on n.g. availability and cost - electric rates can change quickly based on what happens there; and 2) if what you're trying to do is reduce CO2 emissions then nuking the nukes was a Really Bad Move, NIMBYs and Greenies notwithstanding (n.g. emissions might be lower than for an equivalent number of KW from coal, but they're significantly non-zero). The oldest and best "renewable" we have, though, isn't counted in that category and does have a problem during droughts: hydro.