I don't have any direct, conscious knowledge of having done so myself, but I feel that
anything is possible--especially if the dreamer has close karmic or spiritual ties with the other person. Something else to consider (and it may be a stretch for many to grasp), is that the dreamer may think of the person in the dream as someone else, but it could actually be
them in a former life or even in a parallel reality.
We humans are multi-dimensional spiritual beings and when we are operating on "higher" (more expanded) levels of consciousness, time becomes much more flexible--in fact, what we perceive to be linear time may actually cease to be a factor in our experiences. In other words, the dreamer may be somehow accessing the perspective of his/her own past, current, or future self in their dreamlike state.