Currently it is not possible to remove obsolete or old projects from the Wwise Launcher. A simple option to remove projects from the project list is needed for managing multiple projects and reduce clutter.
Imagine a scenario where you pull a clean Wwise repository that also exists in another directory. Now you have two versions of the same project in Wwise Launcher project list. It's very easy to accidentally open the wrong (old) project and working on it without realizing. This actually happened to me and I lost some precious work hours. Ability to remove the older project from the list would have saved me.