This "extraction" supposedly occurred at the Tropicana as the shooting was going on at Mandalay Bay. They don't look like LEOs or military?
Reddit thinks this is a Saudi prince who rented the top floor of Mandalay Bay but was dressing down and gambling at the Tropicana during the shooting.
There are some Crazy theories about all of this..
They look very much like LEOs. There were false reports of other incidents during that time. Someone just caught the response on video.