I agree with you that we should look if we can find a better way of leaderboard.
But I disagree that this is a reasonable change.
The amount of DECs printed for the leaderboard is so small that it doesn't matter.
I have calculated above that with the DEC spent for Rebellion packs (and I count only the sold packs and not the bonus pack and I also take only 4.000 DEC so in my calculation all have used the maximum amount of vouchers) only in the 30 days of the pre-sale we can pay-out nearly 10 years this leaderboard-prices.

Also we discuss the question to put packs in chest or not, so it would be the question to put the packs we reserve now for the leaderboard in the chests.
I understand that we should be carefull with packs in chests but I see no difference if the packs are sorted out for the leaderboard or with reward chests.

What is absolutely clear is that we should not sort out the amount of packs we sorted out with Chaos Legion. When I remember that @yabapmatt calculated for the proposal to prelong the packs in chests with 300.000 packs in 6 monthes, okay it was in the end a bit longer than this 6 monthes, but 300.000 packs in 6 monthes is too much.
But if we calculate the chests new with drastically reduced chance than I think it would be okay and it would be a nice suprise for anybody to get a pack in a chest.
So why not take this reserved 40.000 packs for reward chests, calculate the chances new so that this 40.000 packs will be enough for 12 monthes and let the leaderboard-prices like they are ?