Although...in the cases of both Buffy and Warren, the character was clinically dead, but still revivable, and the First was able to impersonate those characters. (Naturally, though, this is a retcon in the case of Warren-- surely at the time of writing, the writers thought of Warren as killed off for real. And in Buffy's case, would the "death" in Prophecy Girl have been enough, as it was enough to call a new Slayer? Or would it take a more permanent death as in The Gift?) Such could easily have been the case with Cordelia and her coma; perhaps she died, and Jasmine kept her in a comatose state that was really more of a living death, like undead creatures.
Indeed, You're Welcome and the rest of Season Five could remain essentially the same if Cordelia were dead and Angel & crew knew it; after all, Cordelia was dead in You're Welcome, and she (and the writers) could have let it be known from the beginning. Similarly with the episodes from Sacrifice on: The writers could have had Cordy die in The Magic Bullet, claim that it happens in a way that doesn't damage Jasmine, and the rest of the events would happen in much the same way
