I don't think they do. Only Packs bought in-game qualifies for the airdrop.

I tried buying UT packs on Monstermarket before since I thought they would also give some cashback for buying packs, but stopped myself after seeing a pop-up there that says that if you want the packs to qualify for the future airdrops, use the other link that is directly connected IN-GAME. So I think only packs purchased in-game qualifies for the airdrops.