They learn little by pressing "print". However, if the school is teaching students how to create the models and all of the prerequisites leading up to that, then they learn a lot. Advanced classes can expand on that by allowing students to create new object solutions to problems they see.
Oh, and the schools can possibly increase the use of manipulative models in their classrooms by printing them instead of purchasing them from someone else. This also allows teachers to more innovative by modifying the manipulative teaching aids and by creating new ones that may not even be available. As an example, a group of teachers could get together to recreate a miniature section of an ancient city, both in its current destroyed form and perhaps how it might have looked when new and whole. that is something that you don't just purchase from a catalog.