presumably the squad are going to get some warm up time at the stadium soon and the nets are going up ready for it - means they don't need people in the stands to run around after balls and slow down the team exercises. Unfortunately I suspect that the camera will be switched off when this happens.
I am sure they will be brought down for matches. If you look at how close the supports for the net are to the pitch, they will not leave them there in any case at risk of injury.