Quote from void_nothing »They probably won't pull the trigger on him for a while. The lead time on a novella (a short novel, in other words, which is conventionally 20,000-40,000 words) is conceivably about a few months, far shorter than the lead time on a set. In addition, Sanderson invented the character from whole cloth, so there wasn't a way to simultaneously write out a set story treatment with him and have Sanderson write the novella. I would not be shocked if he didn't show up on a card for 4-5 years.
They actually mention in the interview that Sanderson coordinated with Wizards Creative to fill a hole in their new character pipeline. Davriel is definitely getting a card in the next few years.