I think they're going to do what they did in TDB where you use Xur to level up your exotics. If they did make year one exotics obsolete then they would have to make around the same amount of exotics that were in the game at launch. Also, it would make the exotic weapon changes coming with TTK almost pointless.
English
-
Actually, some exotics are going to transfer to Year 2 of Destiny, just not most of the PvP/PvE Gods are going to transfer to Year 2. (Still going to have to deal with TLW in Iron Banner btw + his range/ads focused brother The First Curse)