I thought the Dragons sanctified Teldrassil for the same result.

The dragons have to "bless" a new world tree for the night elves to be granted immortality, they never did this with Teldrassil. Nordrassil was blessed but subsequently sacrificed to defeat Archimonde.

Personally, I would think that renewing the world tree wouldn't necessarily bring back the night elves immortality, it'd just bring back the tree. I assume the dragon aspects would have to bless the tree again.

At the end of Stormrage, Teldrassil does get blessed. However: Nozdormu wasn't there, so they may me mortal yet.

Ofc Teldrassil is a failed world tree. It's in saltwater >

Well considering Nozdormu IS the Aspect of Time itsself, it might be benificial to the aspect of immortality for him to be present

Yeah that's just what need, prissy, IMMORTAL night elves.

Yeah, cause night elves are prissy AT ALL in lore...right? Just cause everyone thinks they look pretty in game, it doesn't mean that they were the pansies of the alliance in lore.

Not only did the Dragons bless Teldrassil and the Night Elves are immortal again, but the starting zone quests in Teldrassil now tell you all about it too.

Teldrassil is healed once and for all even in a climactic battle now where Elune fills you with power herself that lets you walk on water, blast enormous blasts of AOE power, and suck all the surrounding shadow enemies to you. You're basically a vessel for Elune's power and you face a final remnant of Xavius spirit and destroy him once and for all, cleansing Teldrassil before you finally move on to Darkshore.