Since hard pruning puts the bonsai in a state of shock, is it a good idea to keep the plant shaded for a week or so after hard pruning? Or heavy defoliation?

as a general rule yes. but considering the time of season what species are you hard pruning?

The main reason for keeping it out of full sun is to reduce sunburn effects.

I am not sure that pruning puts a tree in a state of shock. Then again, I do not think plants experience shock, as this for me is a more mental thing.