Agree, if they're launching the new book then they will surely be launching some of the new boxes with it (based on the art we've seen probably Shen Long, Ironside and Colette, maybe others). Also, the way that Malifaux works Wave 1/2 isn't really a 'proper' distinction even though it's been thought of that way in people's head. All the rules are already out for all the models save Avatars so they need to get models out for all of them. It would make the most sense to get those which don't have any models, or low supplies of metal models, out first, regardless of Wave. As for Masters without plastics yet:
Von Schill
Tara
Zoraida
Brewmaster (although we have seen this, it just seems to have disappeared into the aether again!)