Edit: Sorry but I messed up, this is for the first DLC coming out in December, not the second one. The expansion is called The Dark Below and the raid is called Crota's End.
I was looking around DestinyDB a while ago and I saw something interesting. There some legendaries there that aren't in the game yet, including what looks like the 2nd raid's armor sets.
Note: None of this is official and could change when the DLC actually comes out.
Warlock gear
Helmet-
Deathsinger's Gaze
Chest-
Deathsinger's Mantle
Gauntlets-
Deathsinger's Grip
Legs-
Deathsinger's Herald
Bond-
Bone Circlet
Hunter gear
Helmet-
Unyielding Casque
Chest-
Relentless Harness
Gauntlets-
Dogged Cage
Legs-
Tireless Stride
Cloak-
Shroud of Flies
Titan gear
Helmet-
Willbreaker's Watch
Chest-
Willbreaker's Resolve
Gauntlets-
Willbreaker's Grip
Legs-
Willbreaker's Greaves
Mark-
Mark of the Pit
You can't look at them in 3D like the other armors, but you can see what they look like through the thumbnail. Some of them have abilities for the Vault of Glass but I think those are just placeholders. There are also other legendaries on the website, including Trials of Osiris gear and weapons. Also if you go to materials section you can see ship parts.
Edit: I wanted to share some other stuff I found, some of it is from the Trials and the others are assorted items I found on DestinyDB
Materials It has ship parts and also templates for
vehicle and
ship shaders.
Examples of possible Trials of Osiris gear, DestinyDB also says that the game type of the Trials is Skirmish:
Trials of Osiris Hand Cannon
Trials of Osiris Legendary Sparrow
Trials of Osiris Emblem I've found three different emblems titled Sun, Moon, and Eye of Osiris.
Other stuff:
XP booster Consumable There's one for each enemy race but I haven't found any in the actual game.
New Legendary Armors There are new vanguard and crucible armors for each class. This one is just an example. The skill trees for them are incomplete though. If you look through the armor sections on DestinyDB you can find all the new legendaries. There are also some legendary
weapons that aren't in the game yet.
This is some more speculation but I found a
Level 28 playlist and the
Crota's End raid, which goes from level 28 at normal to level 32 at hard. I have no idea if it's true or not or if it will change when it actually comes out, but I wanted to share that with everyone.
If anyone wants to see more I recommend going to this
post
Bungie has confirmed the next raid in their weekly update:
""Mythoclast's power tail is long enough for players to rely on in the next Raid. For a player and their group of six who beat Atheon on Hard mode, we'd like the Mythoclast to be a weapon they can continue to rely on in the next Raid,
Crota’s End""