I believe that Dates are on the Foods to Avoid or Eat Sparingly list because they have a high glycemic index.
Once you are at your goal weight and go into Phase III, you'll really have to do some experimenting to see how things affect you... Everyone's body is different. I'm insulin resistant, so things with a high glycemic index are very likely to set off cravings for me, dates would be a very occassional treat for me, but they may affect you differently.
In the meantime, how do you feel about prunes? I love them and they are on the approved list.