For my parents who are fortunately still alive, it is still expected to me that they will die before I do. I have been preprocessing their passing essentially my whole life. I don't anticipate it being a huge emotional hit for me even if it happened suddenly tomorrow. It would suck, sure. But, not unexpected nor unprocessed already.
As for people that commit suicide, I kind of figure they made their own choice. So, I don't usually feel bad when they do so. Everyone's always spouting the "my body, my choice" thing, but we seem to not apply that to people that want to die. But anyways, I wouldn't feel a strong emotional response to that situation either. I've only known one person that actually did kill themselves (jumped out the window several floors up).
I also find funerals terribly awkward. I try to avoid them if I can, but unfortunately that's not always plausible.
Preprocessing of emotions is plausible. You are actually the second person I have met online who has suggested that I do this.