If you need something like this
Do next. Crete Pawn bluerpint. Add Camera component
Add this Pawn to Game Mode
And add this to Pawn EventGraph
You need add index switch for node GET if you have several cameras in your scene. In my example I have one camera and I just set zero index.
PS: You need Play this example in Standalone mode, because in PIE mode Pawn not always attached to Matinee Camera. I think this is little bug.