Is it horrifying for a dead body to be dissected publicly? It must be gruesome, but if that happens to the corpse of someone you knew, is it a reason to take offense?

I don't see that it is. The dissection can't harm the person who died, or per memory.

If my corpse is someday publicly dissected, I think that will not be a reason for to take offense on my behalf. Instead, please support what I have done with my life — the Free Software Movement.