If I recall correctly Screencast Keys was removed because it did not fit with the Blender design guidelines. There is now a version of Screencast Keys maintained by other users on Github, such as the one you have linked.

The fact Screencast Keys doesn't work with recent versions of Blender is probably due to Python API changes in recent versions of Blender making it incompatible. Add-ons no longer being compatible after a Python API change is not the fault of the Blender foundation, but instead simply a issue users experience when using older Blender add-ons. It is up to the add-on developer, or some other user, to update their add-ons to conform to the Python API changes. As such, there is nothing the Blender foundation can do to get Screencast Keys to work in the recent versions of Blender. Instead it is the authors responsibility and as such I will be closing this report.

If you're asking the Blender foundation to add a Screencast Keys, or something similar to that to Blender, then that is considered a "feature request" and we do not track those on this site. Instead you should use other channels for feature requests: https://wiki.blender.org/wiki/Communication/Contact#User_Feedback_and_Requests