Now in December 2018, still there is no command or tool in ArcGIS Desktop to know how a feature class is related to various mxds, models, scripts or any other relationships. I believe it is helpful to have the function in ArcGIS Desktop.
I have created this poll to raise this requirement by the ArcGIS users from different corners of the world. It is a long needed functionality, probably first documented in 2010 in Geonet.
Many people have managed to get it resolved locally through scripting. However a button or a right click command can be a easy solution that ESRI can develop and supply as a built in solution with ArcGIS Desktop to help minimizing the effort of the GIS professionals to create the script.