I noticed the muzzle flashed too. It looks there's one behind the Hazmat container as well, which I'm assuming is from the truck set's third figure. Three figs were listed with the truck but only two are in front of it. I love the potential of muzzle flashes coming with future sets.
It looks like the 2018 NYTF confirmed the Heroes Series 3, care packages, shipping containers, and desert transport truck. As such I imagine the other WWII sets that were listed on Amazon will come out too.