Yes and no. Some of the piece you have to make need to be cast, which means having a forge make the molds, test the molds out, and then, if you find an issue, start the whole process over again. That process can take at times around 6+ months, and more if you find an issue or have to redesign. Similarly, because of the limits of machining, 3D printing allows you have to have much more complex parts and geometries, especially for the engines. I was at GE Aviation for a bit, and they showed us some nozzles they printed that would be impossible to make if not for 3D printing just because of the complex geometries.