With Patch 10.1.5 PTR, Blizzard seems to be giving Naxxramas the same treatment as Zul'gurub in Patch 10.0.7, with new content being added to the old raid zone, including ancient recipes and a brand new mount. Below we are highlighting some of the content found in this first build. Be mindful that this is all datamining and not available for testing yet.
New MountThe biggest addition is Valiance, a new mount that has the source as itself, meaning it will likely spawn inside the old raid. This mount has the model of the mount used by Thane Korth'azz in Naxxramas.
AchievementsA new achievement has been added with the reward «Unlocks ancient secrets within Naxxramas». The achievement requires three quests to be completed and seems to be account-wide unlock.
NEW Empower your Argent Dawn Commission. Reward: Unlocks ancient secrets within NaxxramasThis unlock seems to be unlocked by repairing your Argent Dawn commission.
Category changed from Uncategorized to Item Effect Spell Used by Item Argent Dawn Commission NEW Repair the insignia with a Righteous Orb and 4 Truesilver Bars. Used by Item Grapple?Spell data also references a grapple to be used within Naxxramas, maybe making it faster to travel around the raid:
NEW Gain the ability to grapple onto specific points within Naxxramas. This effect unlocks for all characters on your account. Effect #1 Complete Quest Effect #2 Update Player PhaseUsed by Item
Ancient RecipesSimilar to Zul'Gurub's «return» in 10.0.7, there seem to be new ways to obtain removed recipes from Naxxramas with Ancient Scrolls.
NEW Reveal a random Ancient Recipe from Naxxramas. Used by Item NEW Break the ward. Used by Item NEW Unlocks the ability to exchange Scourgestones with Zackett Read more on wowhead.com