The new voice lines are added in act 2 and 3. Basically Karlach gives up and is ready to die which not only wasn't the case before patch 2, but also is a spit to the face alongside "we did everything we could" because we literally didn't try a single thing
Hh, so in this case Tav should try even harder if he cares about Karlach, but he's obviously not allowed in act3. This is exactly why I would like to wait until DE with proper questline, than quick hotfix quest.
