Actually, I figured out how to do this. As long as your have the poly extrude node selected in the attributes editor with the face that you are going to extrude selected, you can keyframe this!!! Im quite happy as it works like a charm. Technically the extrusion itself is not automated, but any changes to the extrude face like position, rotation and scale are.

For anyone who wants to learn this:

1. Select face
2. Extrude
3. Select Poly Extrude node in attribute editor and press "s" to set keyframe. All of the properties will change color.
4. Move to another frame.
5. Edit face properties like location until set to where you wanted to extrude to.
6. Press "s" to set keyframe again.
7. Rewind and enjoy.

Cheers