Formerly a curator of the Black Armory, Ada-1 will take on responsibilities of selling armour pieces as well as mods for them while Banshee-44 will get some changes to compensate.
Destiny 2 is shaking things up at the Tower in Season 14. Ada-1 will make a return and pretty much everyone is looking forward to completing her bounties in order to turn their existing armour pieces into ornaments.
What we didn't know until the latest TWAB, however, is that Ada will take over some of Banshee-44's responsibilities, on top of some new ones. Namely, she will start selling different armour sets each week, with all of them being from the exploration loot pool. They will have randomised stat rolls so it's possible, but not guaranteed, that we might get a chance at some decent rolls.
Besides the armour sets, Ada will also be selling armour mods, including one per day that is designed to alter combat. Examples of these mods are the ones based on Warmind Cells and Charged With Light buffs. Ada will also sell masterworking materials and relive Banshee of this duty as well.
The old Exo will focus a bit more on actual weaponry, living up to his title. He will be selling a random selection of six weapons that will reset each week. The reason there are six of them is that two are from each category - Kinetic, Energy and Heavy.
Just like Ada's armour pieces, Banshee's weapons will have random rolls so keep an eye out for potentially decent weaponry that is at an arm's reach.