I'd be willing to bet there's something fishy going on here.
Geothermal developers and other industries have been trying to turn that spot into an industrial area for years. Schwarznegger proposed they close it (wonder which of his buddies asked that favor?).
But, it's still a functioning lake and it still has an operating recreational area. Boating, kayaking, etc., are still permitted, so the lake isn't quite as toxic as the industries would like us to believe.
https://www.parks.ca.gov/?page_id=639
It is true we (as a nation) would benefit from mining our own lithium rather than depending on China. China's far from dependable, right?
The Salton Sea is evaporating and it's land-locked, so, given enough time (decades?) it could become a playa. The salinity level is likely increasing due to the evaporation, but folks are still fishing there.
My biggest concern at this point is lithium leaching into the rather high water table in that area as long as Salton Sea is still fluid. Of course, there is no lithium mining without water, so they obviously plan to use the lake water for their mining operations.
By labeling the lake as toxic now, they're presplaining what's going to occur once lithium mining starts. It's a self-fulfilling prophecy.
By the way, Salton Sea is on a migratory bird path, so that does not bode well either.
It will be interesting to see what happens here.