Chapter 15: rail_test is not used; models in the notebook not evaluated on the test set

[tc-git-1]

In the code for Chapter 15 of handson-ml3 at
https://github.com/ageron/handson-ml3/blob/main/15_processing_sequences_using_rnns_and_cnns.ipynb

I see code that creates that train, validation, and test sets.
rail_train = df["rail"]["2016-01":"2018-12"] / 1e6
rail_valid = df["rail"]["2019-01":"2019-05"] / 1e6
rail_test = df["rail"]["2019-06":] / 1e6

I observe that:
• rail_test is never used in the notebook.
• The models created in the notebook are not evaluated on the test set.

Q. Why are the models in the notebook not evaluated on the test set?

Q. Should the models created in the notebook be evaluated on the test set (rail_test)?