Something interesting on the rear of a Surfliner

On Saturday April 1, I caught a southbound Surfliner in Laguna Niguel with what looked liked to be two Creative Charter Cars (one had a dome) and a GE Dash 8-32BW in the Phase V Scheme trailing.

Are these cars privately owned? Also why would a GE be tagging along?

Or is Amtrak trying to “Mix Things Up” since it’s the weekend?

Just wondering