I don't think the article is suggesting aircraft carriers have a big fabber below desks that will print you out a new aircraft. I expect it will be used in the first instance to reduce inventory for all the spare bits and pieces, and it will be asked to make a new handle for the coffee jug. But I reckon this could go a long way...
The big drop forges are used to form and work-harden material in one blow. If you have a press that is big enough to whack out a whole aircraft bulkhead in one go, then you end up with a thin, light component without any heat-affected zones from welds. That is pretty good way of making tough microstructures provided you can chose your atoms so they form the right sort of microstructures by themselves. You can, in theory have aluminium alloys with carbon fibres in them, but you cannot get them by conventional techniques. But you might be able to lay down sprayed metal and fibres and design your microstructure from scratch. It will probably be slow because you haven't got the massive parallelism of all the atoms doing the right thing for themselves, but it will get us into places that drop forging has never gone.
The other thing we can do is to make complicated internal structures. Our bones have a lattice of tiny struts that are continuously broken and repaired, which is how they optimise their strength. People have made a similar structure for a car bumper. It took a day to print a bumper but it had millions of little struts that absorbed energy as the bumper hit something and crumpled, in a way that a bulk plastic product never could. I can imagine aircraft wings could be stiffer and yet fail in a controlled slow bending rather than buckling if they were made like this. One day we could even mimic the regeneration process of our bones.
I suspect the actual story is nothing like as exciting as this. But it is a beginning.