This sounds like an excellent idea. However, what about choice of material? We pick a musical piece to learn because we enjoy the tune and how it sounds. How should a beginner choose which code to memorise?
"Tensorflow: This is the finest Google codebase I ‘ve studied. Great design, very high quality code, and easy to understand how everything fit together."
Tensorflow is the worst code you can learn from a library design perspective.
A curation of good codebases by someone who studies a lot of them.