I understand the need for this change and I like the way you decided to handle it. This new loot box system actually allows a player to grow the diversity of their collection a lot better:
Before the change I can earn reward cards and if I'm in the top 50 players I could also score some packs. That's it.
After the change I will still get some reward cards but I'll also get DEC which I can use to buy any edition card on the market (or packs, or orbs, or whatever else I want to do with my DEC). I'll also get potions. Some potions result in extra reward cards but some also will get you Untamed packs and Orbs, not to mention a chance of getting the special edition mystery reward drop cards.
Seems a lot more fun way to give out daily and season rewards than just a load of reward cards. I welcome this change. Also happy about the increasing sponsorship opportunities. Sounds like we might see some Steem Engine tokens and other interesting goodies in our loot boxes in the future.