I have to believe they will revise the rates based on EV Project experience because they want people to charge at night, and those rates provide little incentive to do so. On the basis of equivalent gasoline price*, the EV-TOU rates are about $1.20/gallon super off-peak (midnight-5am), $2.10/gallon peak summer, and $1.40/gallon other times. Good prices compared to oil burners. And enough incentive to fill up at night whenever you can. But 20 cents a gallon isn't enough incentive to forego filling up whenever it's convenient.
Worse (for SDG&E) since so many EV owners have solar panels, we can just go back to DR rates with enough PV to keep rates in Tier 1, for an equivalent price of $1.20/gallon 24 hours a day 365 days a year: no incentive whatsoever to be "nice" to the grid.
My guess is that their data from the experimental EV Project rates will show that people with a large peak/off-peak difference charge overwhelmingly at night, and people with a small peak/off-peak difference or who are not on TOU rates do not.
* Based on 4 mi/kWh EV, 30 MPG gas car, 87% EVSE efficiency (3.3/3.8).