From what I recall in GTS and what we've seen of GT7's license structure, it seems highly unlikely that we'll be able to transfer licenses. For one thing, I only recall there being various stages in GTS, and not any actual licenses to earn, whereas GT7 takes an approach much more like prior games.
Honestly, I'd be fine just starting clean in GT7, without any bonuses for having GTS. It just feels more natural to me, y'know?