What makes you think so? Have you tried it? I attempted to run a Plantmax HPS DE bulb with a 2013 Xtrasun Dial-A-Watt 1000w ballast. It flickers pretty much continuously at 1000 watt setting but was apparently stable at the 750 watt dial setting. Based on a conversation with Solis-Tek, it is my understanding that the operating frequency of digital ballasts is inversely proportional to the wattage selected. Not sure if that is a linear relationship, I didn't bother to graph the data.A mag ballast should be able to run DE bulbs no problem.
Since almost all magnetic ballasts are operating at relatively low frequencies, I have no expectation that they would fire a DE bulb, as those are known to require high operating frequencies. I did not expect the Xtrasun to work with the DE bulb, I just tried it anyways. Ballast manufacturers do not generally advertise the operating frequencies of their ballasts.