Don't complete it until the DLC releases!!
Planet Destiny confirmed that when you turn in an exotic bounty after the release you will receive the version 2.0 of that weapon!!
You won't need to waste your shards to upgrade it!
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If this is the case I'll have 2.0 versions of thorn, pocket infinity, and invective and two more exotic shards. If not I have a 1.0 pocket infinity and two more exotic shards. Haha.