There are rumours that the interchange will be reduced to 6 very shortly. I was always on the cards. First reduce it from 10 to 8 and then reduce it to 6.
If/when this does happen, props are going are probably going to get lighter. Big props won't be able to play long minutes. This could be a concern for someone such as Boyd, who doesn't play big minutes. Someone such as Pangai would probably become even more valuable as I think he can play big minutes. Sam Burgess's value could increase.
I do remember back in the early 80's (I think it was 82) when they had the players weight and height on the back of the footy cards. The heaviest player in the comp was Don McKinnon. I am pretty sure he weighed 112 kgs. I think Pat Jarvis who was an origin prop and a great player weighed about 96kgs. I think Craig Young was around 102kgs. In the 80's clubs could only make 4 replacements and once a player was replaced they could not come back on the field. Reducing the interchange to 6 will change the game. Smaller players will benefit. We may see more running from dummy half. A player such as Dufty could become very dangerous from dummy half late in the game.