Hmm, interesting. o_o
I don't know how many deathfics I've actually read, but yes, the heart of the tragedy would be Clark's feelings. It likely wouldn't be Lois herself per se, since she being dead has either gone to a better place or, at the very least, "feels no more pain"; however, there is something to be said for the impact she should have left on the world, and the Lois-shaped gap she'd leave behind.
Comparatively, what fics I've read in which Lois is a ghost, and thus grieving for herself and her life lost, tend to either not be tragedies or not stay that way; because as long as Lois is somehow able to participate in the story, we know that somehow she and Clark will find their way to each other, either in life or in death.
