You wouldn't need to talk about all of his previous incarnations, but the details relevant to Ten's life would be important. For instance, we don't need to know about the day-to-day life of Four, but we need details about him coming from Gallifrey, about having the TARDIS, about this being his tenth incarnation, and the Time War. So basically the information that's relevant to Ten.

Nine may have to come into it a little since Nine is the one who met Rose, Jackie, Mickey, and several others. But the focus should be Ten.