It doesn't look real to me. I've seen the making of the Two Towers and Return of the King too many times to believe my eyes when it comes to this ****. There are too many changes from RO the trailer/promo material to Rogue One the final movie (Saw's entire appearance, Vader without tunic, Krennic mouthing off at Vader aboard a Star Destroyer interior looking setting, Jyn and Cassian running on the beach with the disc, etc. etc.) to make me not believe some things weren't last minute additions, no matter what the "real" making of story is.
Such a weird argument for you to be making. They filmed on location at the Maldivian Islands and their death is clearly on a real beach. It's not a complicated thing.