There seems to be a limited amount of YEAR 1 exotics that get the TTK upgrade. For now we know its Last Word, Hawkmoon, Red Death, Truth, Thunderlord, Suros regime, Bad Juju and some armor parts. The upgradeable old exotics will not only get the new dmg values, but some will recieve significant new perks. Especially the armor. To put it as simple as possible. You will be able to "store" the old weapon in the special blueprint window and be able to RETRIEVE them at your liking anytime you desire. They will tho come NOT LEVELED. At the same time if you aquired for example a SUROS regime that is being able to be upgraded in the TTK you will be able to GET THE NEW VERSION asap with like 120 legendary marks.