Yes, we would pay less taxes on players' salaries. So for instance, let's say that a player makes 4 million net a year. Juve has to pay 8 million in total for his wages, 4 million to the player and another 4 million to the Italian tax authorities. When the law passes, Juve would only have to pay 6 million for the same player (if I remember correctly), 4 million to the player and another 2 million in taxes. This is going to hugely beneficial to Italian clubs since they lack the revenues of EPL and La Liga teams whose tax rates are higher.