in preparation for the light level increase including higher rewards from faction packages does it make sense to leave unclaimed faction packages in the tower? or will they end up being at current levels?
Packages/engrams will decrypt in to existing gear only as confirmed on the stream and Weekly updates. You're better off leaving ~10XP to your next Rank and then doing a quick patrol, or trading a bounty. There is one way saving packages/engrams will benefit: it will increase your Cryptarch rank, which will net you updated light level Cryptarch packages if you decrypt a bunch after the update.