About the only electric garden tool I own is a hedge trimmer, and I run it off my gasoline generator. I image that this is how the people in CA will side step the new laws.
If I understood correctly, the California ban applies to all small gasoline engines including portable generators. I think in future, portable generators will need to be battery powered 
Pretty sure there are many videos showing an electric motor driving a generator with a feedback path to drive the motor and enough left to run your house. So no problem there.
Our small 2-stroke Lawnboy mower is over 40 years old now. I can't see moving to a plastic electric mower just yet and spend my time swapping batteries. Hard to beat the power density of gasoline.
I had one good petrol mower years ago.
All the others have been rubbish.
They overheat after a short period & you have to spend ages getting them to start after they cool down.
I could never afford a Honda, so ended up with Briggs & Stratton or Tecumseh engined things.
I have fixed, serviced & rebuilt all sorts of car engines, but for some strange reason, I have trouble with small engines.
I eventually gave up on them, spent the big bucks & got a Ryobi "plastic" battery lawnmower, & have been agreeably surprised.
It handles my overgrown backyard just as well as the petrol ones, & if it "bites off more than it can chew", the motor "stalls", but you just pull it back from the overloading vegetation, push the "go" control, & away you go.
The petrol engines would stall, decline to restart & flood if I insisted.
On a warmish day, by the time I ran out of fuel, they would usually be hot & again refuse to start, necessitating a prolonged cool down time.
With the Ryobi mower, when the battery goes flat, I just remove it, take an extended break until it has charged, slap it back in, & I'm ready to go.
If I were "flush with funds" I could have two batteries & never have to stop.
Interestingly, the petrol mower which worked properly was an old 1960s "Rover" with an Oz made 4 stroke engine of unknown provenance.
It also had, as was common in those days in this country, a starter handle with which you wound up a large spring, then folded the handle down & bashed it on the top to start.
It would deliver all the stored energy in the spring very quickly, spinning the engine up to speed fast, almost always starting properly.
All the later ones had those godawful "pull starts", which require you to brace the mower body with your foot & heave on the cord umpteen times, till it either starts, or you get heartily sick of it & go inside & have a coffee instead.