Yeah, that's my guess too -- Descent is clearly still selling, but it seems like they have shifted the design teams over to licensed stuff like the Star Wars descent clone game, etc.
Personally I'd just like the remaining D1 heroes ported over in an app friendly expansion for newer players (I don't have the first edition and don't want to buy the conversion kit since it doesn't work with the app, but would still like heroes like Red Scorpion etc). And I'd like to see more app campaigns developed. There's a bunch of content released though so hard to complain just because there isn't more.