Regulated use language frequently refers to power-driven equipment, which generally are machines that use internal combustion engines. It doesn't specifically include battery-powered equipment and other equipment powered by an electric motor.
In either case, care must be taken when operating equipment — whether gasoline-powered or electric — in dry vegetation. Don't rest the power head on dry grass or other litter, and watch for spark-caused ignitions where you have recently been working. Even battery powered string trimmers have sparked fires in dry grass. Also take care when using electric hand tools near dry vegetation. Even battery powered tools can generate sparks, which can cause a wildfire.
You may be OK to use electrical equipment in dry vegetation after the posted shutdown time, but if the equipment causes sparks that start a wildfire, you'll likely get a citation and a bill for fire suppression costs.
Always have a water supply or fire extinguisher at the site where you'll be using equipment, and do a fire watch after you shut down.