The FSO/OWC channel components can be thought of as a subsystem, which consists of a transmitting telescope and receiving telescope with the free space propagation occurring between them. The spatial analyzer does not detect a change in the profile, because it is detecting the output of the receiving telescope, which realistically has lenses to refocus the light. The beam broadening over large distances is modeled as a power loss. Take a look at the component help for the FSO and OWC components to see exactly how the loss is calculated.
If you want to observe the beam broadening over large distances (i.e. km’s) you would have to write your own Matlab model. If however you are interested in the um regime you can use the Spatial Connector.