OP: This is an assumption. I don't think it is so much the licensing that is the problem with real tracks, however the accurately mapping out of the track, and the work involved to do it. It's not just the corners and track proportions, but also each hill and every bump and surface change would have to be mapped, and that takes a lot of work.
If and once the real track is implemented into Live For Speed, people would start complaining about how "there should be a bump here or there," "the cobble stones are too slick or not slick enough," or "the crest doesn't go that high or not high enough." These requests would just pile up just like in the other sims.
However, it would be really nice to get either of the two (Nurburgring or Monaco).