Outlook still utilizes that Journal folder, however it is not readily available. Meaning it doesn’t show up in the Navigation Pane as it used to.
To have access to the folder, you can click on the dots next to the Tasks tab in the Navigation Pane and then click on Folders. This opens all folders available, where you should also be able to find the Journal one. Alternatively, you can still use the CTRL+8 keys to gain instant access to the Journal folder.