I feel as those who decided to not buy booster packs will continue to not buy them regardless of what system is in place. Same goes for the ones that buy boosters in the hundreds. They'll likely continue to buy boosters regardless of what league system is in place as the value is the card itself. What we win with them is "extra".

But for the ones who like to buy a booster or two here and there I believe the purposed new league system will encourage them to do so more often. I base this on something very simple, everyone likes winning.

Once the Bronze level players see they have a chance at some extra prizes in a league of their own they will likely come to the conclusion they need max bronze level cards if they want to be the best Bronze player. So they then go out and max their decks to said level. The same goes for those who want to play in the Silver / Gold / Diamond leagues.

What happens next is the top players from a league will eventually want to move to the more prestige league above their own and the cycle continues until they are able to max their deck.