This is true in theory, but in practice it makes little difference.
When California has increased demand, so do all the states it's connected to. Hence the rolling blackouts a couple years ago and more are expected for this summer.
Most blackouts in California are not driven by electricity shortages but rather by hot and strong wind events that lead electric utilities to shut off certain transmission lines in rural areas to avoid sparking wildfires. This distinction probably doesn't matter much to those who have their power cut but it is important to actually fixing the root cause.
There was a particularly nasty heat wave in the western US in 2020 that did lead to load shedding due to a shortage of electricity. That was the first time California had load shedding since 2011 IIRC, and it did not repeat in 2021.
> Hence the rolling blackouts the last few years and more are expected for this summer.
California has had two days with rolling blackouts since 2001, August 14-15 of 2020.
It has had public safety power shutoffs in some areas since 2019 to prevent fire risk during dry, high-wind conditions, but those are a different issue than rolling blackouts and unrelated to energy generating capacity.
When California has increased demand, so do all the states it's connected to. Hence the rolling blackouts a couple years ago and more are expected for this summer.