But most consumer gear that sucks down power isn't WiFi- or Bluetooth-equipped, and making it so would add another $20 or more per unit.  Antennas, precision timebase, fast microcontrollers, FCC/DOC certification,...  Add the hassle and problems of configuring the meter and controlled loads to talk to one another.  Then consider apartment buildings or the like where the meter is perhaps at the far end of the building from the loads, and these capabilities would likely go unused.

Ideally, you'd want a low-bandwidth channel over the electrical line itself.  How about X10? A naïve installation could plug existing sheddable loads into appliance modules set to a well-known house/station code, and the meter would send the commands to turn those loads on and off at the appropriate times.  In an intelligent installation, the meter might merely broadcast the information received from the utility and some other controller, perhaps even a home computer, would schedule and coordinate power use among smart appliances.