Information Delays always have a specified Initial Value. The Initial Value is assumed to have been the value of the input signal prior to the start of your simulation. That is, it is the initial output of the Information Delay element. The default is zero.
The ability to define an Initial Value is important since the actual processes that you will be simulating may not necessarily start when your simulation begins. That is, in many cases, the process probably will have been ongoing for some time prior to the time that you decide to simulate it.
As a result, whatever your Information Delay actually represents (e.g., a perception, a forecast) will have some real value at the start of the simulation, and this value is not necessarily zero (the default). Therefore, you should take care to properly define an Initial Value for your Information Delay.