Details were not shared, but the assurance was that current stuff could be brought up to the same level as newer gear. It’ll likely be through some form of upgrade system and/or modifications, so whatever you’re doing right now you should keep on doing it. Of course, there’s always the possibility that you’ll still find an even better gun waiting for you… but at least then your old Legendary item will be replaced by something other than the launch of a new expansion.
Destiny 2 might signal to most players that it’s time to bring their favorite guns to the nearest trash can while listening to “Amazing Grace” on the bagpipes, but perhaps it’s not time to put old Vera out to pasture just yet. A recent interview on PC Gamer confirmed that players will still have a use for their existing top-end gear when Forsaken arrives, and hopefully not just to while away the time until a better gun shows up.