I really doubt anything to do with the wings would be manufactured in 3D printing. Although it has progressed a lot, it still is quite immature compared to traditional manufacturing. There are many fancy new 3D manufacturing techniques that could achieve near bubble-free result using EBM and further strengthening with exotic methods. But it's still not as strong as components from heavy presses. Weight bearing parts like those in the wings and those used to connect wings to the fuselage sustain immense stresses, 3D printing just isn't that mature to handle it yet. Maybe give it another 10 - 20 years, then it'll be mature enough.
You know, I'm of the same opinion. Although its possible to use 3D printing to form some pretty remarkable shapes without the waste associated with conventional machining, there are cases wherein the manufacturing process contributes significantly to the strength of the finished part.
Stampings, forgings and extrusions are typical examples of these.
Yes they require forms, molds and dies (I worked in tool-and-die), and yes those are expensive - especially if the production run is limited.
But processing your materials in this way adds considerably to their strength, especially if you desire it along a particular direction or axis.
Stamping, forging and extruding the part, results in improvements in the grain and density of the piece (microstructure), particularly if the material used (steels, titanium, aluminum, other various alloys) can work harden or strengthen and the forming process is designed to favor this effect.
Achieving this by 3D printing seems difficult to me. Perhaps one can form the piece by 3-D printing, then finish via, stamping, forging or extruding it to the final, finished form.
Just my 2 cents.
