Unsure about California, Most of Illinois requires a Licensed Stationary Engineer on site with high-pressure steam service.
A building that I worked in retrofitted from HP to low-pressure steam for that reason.
But shutting it down to zero-zero, dehumidifying it and leaving it be would not require watchstanders, nor as much money as stripping the site bare.
But, in the link, they mentioned the problems of GE’s H model gas turbine co-gen plants - apparently much harder to startup and shutdown than the later HA models. Fine, Siemens and Mitsubishi have made design errors as well. Just leave it in standby.
Now, all GT overhauls require new parts as well (blades, burners, nozzles, and other consumable items that wear out i the hot gas path.) Fine, it still has operating hours in it.