Pig lung transplanted into a human

I'd take it over dying. (Not that this technology is actually at a stage where it could prevent that, but neither are whole 3D printed lungs.)

Then you’ll need to wait

3d printing is not the approach that will yield organs. My money is on the work Michael Levin is doing on bioelectronics, where you essentially “command” (/convince) cells to turn into the organ you need by talking with them in cellular electronic language.

My mind-reading senses tell me parent might be thinking about the scaffolding approach where you show cells the vague outlines of a lung or heart in the form of an extracellular matrix and then they go "hmm, we are building a heart then".

If I remember correctly you need both. Program the cells to be X organ cells, and provide a scaffold for them to grow on.

that seems like a way harder problem than convincing your body not to kill the pig organ

Well yeah, but it's plausible that this is easier to get working. If we can get animal organs working, then we can save lives while we figure out how to print/clone human organs.

If you really needed a lung you would take what you could get.