Beginning in R2023a, the product documentation is no longer installed by default (see here). A side effect of this is that some example datasets are no longer installed by default. You can still access them by either installing the documentation, or by finding an example in the online documentation that uses that file, and then use the 'Open in MATLAB Online' or 'Copy Command' workflows to open that example (along with any associated data files) in your MATLAB instance.
Here are 2 examples that use Data_Airline.mat
Copy the command and run it in your MATLAB Command Window.
The example and supporting files will be download to a local folder. It will open in MATLAB, and your Current Folder will be changed to the example folder. If it is a file you use often, consider adding the example folder to your MATLAB Path.
