At this moment I’m going to make this very brief as it’s 3am but I will rewrite all of this and reference my sources for the following guesses.
The Black Armoury: The character on the promo cover of the DLC is part of the crew the drifter use to run with, the crew that the hunter is using the drifter as bait for. And the weapons that will come out in this dlc, or at least some of them will be from the Light vs Light age. The only source of such weapons is the drifter. He has apparently checked that he’s the only one. However he may have gave weapons to his old crew to gain their trust, hence why the dude in the photo is an old crew member.
Jester DLC: The drifters true motives will finally be revealed. If you don’t know he’s using us to kill monsters and bank motes which he then uses to make a compressed one that gives him the ability to summon and control the prime-evils. How this motivates will play out, if he’s gunna go full bad and attack gardeners, use them for the towers benefit or uses them as an ace up his sleave incase any one on his long list of enemies comes looking I will keep looking into/thinking
I apologize, this is reallly bad and vague, it’s 3am and I’m extremely tired and exhausted and wanted to get this down. I’ll completely revise and do full detail once I can write and properly function