The logic goes that since Teldra's body is nearby, and her soul has been "saved" by Vlad as a part of Godslayer, that it might be possible for Verra and/or The Necromancer to reunite the soul and body and restore Teldra to life. This is not a standard revivification, and might require divine intervention. But a very similar operation was performed in Vlad's presence by Verra in Taltos. (Maybe the key difference here being that Aliera was not killed morganti, as Teldra was. But then Vlad could have asked if that mattered.)
In fact, Vlad seems to be thinking along these lines himself while in the midst of creating the Great Weapon. He mentally travels into Godslayer and binds up the "threads" of Teldra's conciousness, in an attempt to save her.
This experience seems to convince Vlad that whatever of Teldra's soul is left is not vital enough to restore her to life as she was before, the best he can do is to incorporate what's left of her into Godslayer.
Would Vlad have inquired with Sethra or Verra or The Necromancer about saving her after his experience in trying to save her himself? Would he have at least tried to bring her body back for a proper funeral?