but I think that they shouldn't necessarily release a new card set yet, instead letting some scarcity set in
THIS. 100%. People keep forgetting how many unopened CHAOS packs are still out there. An F'ing S**T TON. Why would people pay full price for Rebellion when CHAOS packs are so much cheaper on the secondary market? They need land to soak up as much cards as possible and I hope they succeed in doing that.
I still have something like 500 RWs unopened. :D
Land is definitely needed and it has to encourage people to stake their cards, but also give room for people to want to buy cards to play. Hard balance to find.