Good point.Anyone who's ever played a computer game would assume that headshots do extra damage. It's just the way it is...
You shouldn't assume that, because they are new to 7d2d, that they've never played any other games.
They will actually expect more damage from headshots so they will try to target the head. Since they do a lot of damage regardless of location it may surprise them if they find that out ultimately. Still their chances of survival are at least as good as they had been in A16 if everything else were the same.