There is no new rule as far as I know it's just that the interpretation of what is a forward pass has changed in the eyes of the officials because of some video work done by Australian coaches. Basically, because of momentum, a ball passed backwards will actually move forwards in relation the field of play so referees have been told to watch the hands of the player making the pass to see what their intention is.
I think that if a pass looks forward,it should be deemed a forward pass. Never mind the position of the hands.It 's worked well for over a hundred years, Why complicate things now.