Aside from Gjallarhorn, we have 0 proof on what exotics are being left behind. Most of you are thinking that because Thorn or Ice Breaker or No Land Beyond weren't shown in the Year 2 weapons listings, they aren't being upgraded. However, that is not the case. In the stream, there is a split second moment where DeeJ hovers over the Starfire Protocol Exotic Chestpiece, but it is darkened and says "Requires Discovery". This leads me to believe that all the Year 1 Exotics are shown in the Kiosk, but not the Year 2. DeeJ's guardian during the stream had only been given a Red Death, Last Word, Truth, etc in that test build. This unlocked the Year 2 versions in the Kiosk, and so they appeared in their appropriate slots. TL;DR - [b]More Year 1 Exotics will be upgraded than what we saw in stream.[/b] Besides Gjally, nothing is confirmed as left behind.