... why though?
It's not like you're not having to grow the same amount of cells, etc, so you might as well just grow them in aero-/hydro-ponic systems...
It's combining two technologies. One for vat grown nutritional plant cells, and one for turning that vat grown cell into palatable shapes and textures.
It's an interesting tech and the more of these we try out, the more likely we'll find something that succeeds.
I'm not the researcher, so it could just be that this was the most convenient option for their lab. Or it could be that injection molding creates too dense of an object to have the right texture.
Unclear based on this article, but my best guess would be that the portability of a resin based printer and the detail that it allows for is a good compromise for on-site food printing.