Like any other Widget of ArcGIS Web AppBuilder, if we can have this option to add multiple splash screen then this will be helpful in many scenarios For example, we can define one splash screen to be displayed when we hit the application for some general notification to user about the environment and other when application is loaded related to application specific notice.
Also if we can define the location of Splash Screen and add some Title as well then all this will make it much more usable and flexible.