It hasn't changed for at least 50 years, and the biggest change was to outlaw the flick pass back in about the late 1960s.
There has never been a prohibition on handballing above your head, the fundamental is that you hold the ball in one hand (can be, and has always been, a moving hand) and hit it with the clenched fist of the other hand. The issue is that players now use a technique whereby the hand holding the ball is stronger, in terms of the momentum imparted on the ball, than the clenched fist hitting the ball. This is not technically against the rule, and never has been, but it is a change in technique. In any case, how do you write a rule which somehow states that the clenched fist hitting the ball must be the determinant of where the ball goes and how much force it goes with?
I'm all for calling out throws, it is a blight on the game. But citing fictional rule changes weakens the argument. Just enforce the rule as written, you must strike the ball with a clenched fist, not just chuck it out.
DS