If propeller-driven planes with electric engine became the norm, would descent for landing with the engines turned off become a routine procedure?
It's unlikely the pilot would be switching the "propulsion master" off, but it's very probable that "idle power" on the throttle or thrust lever would in fact be a stopped or stopped/feathered motor.  It's likely that regen braking would be electrically available, but it's probably something you wouldn't want to use in flight, for the same reasons you don't engage reverse thrust on jet engines before touchdown (in fact, there are some aircraft where you do, for a subset of the engines, in part because of the time needed to engage reversers).

Having instant throttle response available is very important, so "off" shouldn't be the same "off" you'd use when parking and tying down -- but having genuinely zero thrust could be useful for certain kinds of approaches (others, you want/need to carry some power to ensure you stay enough above stall to maneuver without steepening the glide slope).