Keyboard navigation and screen-reader semantics in notebook cell workflows vary between classic Notebook and Notebook 7

Jupyter Notebook 7 is implemented with JupyterLab components, so accessibility behavior in the notebook cell workflow follows the JupyterLab front-end architecture rather than the classic Notebook template. Classic Notebook and Notebook 7 expose different DOM structures and focus management models to assistive technology, leaving an unresolved decision about which release line should be treated as the supported accessible target.

JupyterLab exposes a command palette and configurable keyboard shortcuts, but the accessibility of dynamically rendered notebook outputs and interactive widgets is not uniformly guaranteed by the core interface alone. Version-sensitive behavior arises because Notebook 7 tracks JupyterLab releases, meaning accessibility fixes may appear in JupyterLab before they are packaged or documented for Notebook users.

Which release line should be treated as the supported accessible target for deployments requiring keyboard-only navigation and screen-reader compatibility? Do cell focus, run state, and output region announcements behave consistently between classic Notebook and Notebook 7 on the same content? What documented accessibility limitations apply to the specific deployed version when using dynamically rendered outputs?