No worries, I am by no means an expert either! Based upon the (not very detailed) documentation, that command prepares the model somehow. From the docs:

the Earth Engine CLI has the model prepare 2 command that wraps an existing SavedModel in the required operations to convert input/output formats.

So I think probably all this step is doing is adding a preprocessing step to the model and saving it again as a new model. The deployment step comes later, I didn’t include it in the notebook.
Based upon the stack trace it looks like the earth engine command line tool (which is just a Python library) imports tensorflow and tries to add this preprocessing step, but fails. There are a few issues (e.g. https://github.com/tensorflow/decision-forests/issues/14 3) with similar error messages which makes me think that there are custom Tensorflow ops required that are not being imported, which causes it to fail.