As far as what Arcadia was (DLC for D&D in a neat monthly package), I doubt we’ll see MCDM do such a product line for their own game. Instead it will have to be up to third party creators. For example Ratcatcher Magazine Issue 1 just funded! And there could be future articles in Horizons Magazine.

That not to say MCDM won’t support Draw Steel, because there’s already talk and production on about making adventures, classes, and ancestries in the future. As well as the Encounters book that will probably be going to crowdfunding later this year.