In Blender 2.81.16, AN 2.1.5 connecting a 3D Viewer to the Distribute Matrices does nothing - you would expect there to be 16 here...
In the following animation from the Animation Nodes docs it looks like a plain axes is being manipulated. However, there doesn't seem to be anything connecting a plain axes to the nodes.
Am I missing something that is assumed about the setups shown in the Animation Nodes documentation?
For comments...the setup!