Bungie will remove one of the best ways to farm progress up in Destiny 2 once The Witch Queen launches, forcing players to grind progress elsewhere.
Destiny 2 sometimes presents players with ungodly amounts of grind in order to achieve certain goals. This happens often with Exotic weapon Catalysts, which leads to players looking to cut the misery short and the answer for this particular issue presented itself withing the Shattered Throne dungeon.
It is the hallway filled with Taken Thralls that respawn infinitely, letting players farm up experience and progress quickly, provided they manage to keep the ammunition count up. Some of the grindiest Catalysts, like the Sunshot one, were completed without too much hassle in the Thrallway but that method is going away with the WQ launch.
Bungie announced that investment rewards like Glimmer, Engrams and experience will no longer be available from the Shadow Thralls and while they didn't explicitly say progress for Catalysts will not be achievable here, the next sentence in the TWAB hinted at it heavily.
The reasoning here is that the devs want players to complete weapon-related grind through activities, bounties and other content, rather than just opening an instance of the dungeon solely for themselves and getting the progress done that way.
As such, players will need to find other ways to grind out XP and parts of the community already have a few ideas.
There is a bright side to this as the changes pretty much eliminate AFK farming but it remains to be seen if Catalyst farmers will be punished for it as well.