Yes. You can adjust adjust your configuration file according to here to get the classic notebook installed.
As to when it changed (sixteen days ago at present), you can see more about it in the post on this forum ‘Notebook 7 on mybinder.org and repo2docker’.
Just to clarify something important in your post:
This link https://mybinder.org/v2/gh/QuantumLab-UChicago/CCC_2024/HEAD?urlpath=/tree/CCC_pythonBootcamp.ipynb is not opening to JupyterLab at present. That is Notebook version 7+ that you are seeing (until you adjust your repo like discussed above). Check the ‘About Jupyter Notebook’ under ‘Help’ and at present you’ll see Version: 7.2.2.
If you go to ‘View’ > ‘Open JupyterLab’, then you can open JupyterLab interface from the Notebook interface without editing the URL in the launched session.