"de-energization" doesn't say anything about the reason either. Using overly-formal worlds is PR spin tactic to suppress the connotation of the common term, and psedo-justify the action by connoting scientific credibility.
PG&E has been pretty clear about the fact that their unlimited financial exposure to fire damage is the core cause of these blackouts. Rolling blackouts implies some sort of issue with power generation, which isn’t the actual cause.
https://en.wikipedia.org/wiki/Rolling_blackout