Some distributors have posted their Aetherdrift order pages and revealed that starting with Aetherdrift, the booster boxes will have 30 packs instead of 36.

I believe it's been stated that the per pack MSRP will not change, meaning the overall box price will just go down accordingly by 1/6th.

A Duskmourn Play booster box is $138 on TCGPlayer, or $3.83 per pack. They are $4.25 when bought individually.

The new MSRP for Aetherdrift $5.50 per pack. If they keep the same price of $140 per box, that would work out to about $4.66 per pack when buying a box. And if they left it at 36 packs it would cost about $168 per box which I think everyone in the world realizes is just far too expensive to buy.