“This conversation was very productive.”
Tev came to the realization that if the Lich King was actually strong enough to counter the forces of Azeroth and stand against the Legion he wouldn’t need the Ebon Blade.
This is about as much tact as he can handle.
from what I recall of the storyline, except for the Ebon Blade, Tirion Fordring (who is not deceased), and those that vanquished the Lich King (Arthas) are the only ones who knows that the Lich King (new one) is still alive, so he might have the power to vanquish the Legion, however that would mean possibly bringing a new evil (secret to light). Just a possible explanation.
Yeah about Tirion…