i’m sure this is possible on the client side that is your local machine would be the only place it would record. not sure how much processing power it would take for a full match. Its not always easy to bake keyframes in most 3d applications. So it should be the same for an actual engine.
There is a possibiliy for them to impliment a snapshot system. But you’ll only be able to view that one frame after the game has ended and it will probably take a few seconds to record that one frame.
I always liked photomode in games.but multiplayer is a live feed. Which means if you stop to take pictures everyone else would have to be paused or be in a forced pause.
I’m sure the devs are doing this all the time to capture their marketing materials but they are probably playing through the unreal engine.