Her dissapproval sits deep

But I agree, the bodies should vanish after a while - not just companions, dead enemies too.
And while I don't do that often in BG3 (did it a lot on BG 1 & 2 to split up companion combos and just keep the good companion), I would like to be able to get rid of a dead companion, who is in your group. I don't think, you can do that right now.