During filming, director Tim Miller had to tell Linda Hamilton to stop smiling when she was firing guns.
Linda Hamilton's first movie where she gets top billing. This is the first Terminator movie where Arnold Schwarzenegger is billed second.
(at around 6 mins) Mackenzie Davis was really fully naked on set in the scene where Grace fights the cops. She admitted in an interview that she didn't feel awkward about it at all and even said it was a cool experience even though she was nude for several hours. Despite the state of undress, the actress decided to just enjoy every minute of it. She even opted out of wearing a modesty garment which is typically used while filming nude scenes. She described the garment as "disgusting underwear" and that putting it on was like "trussing a turkey." Davis decided to go without the garment because she realised that it was "so much nicer to just be nude and not sort of embellish it with these weird lines." She added that being naked in front of so many actors and production crew and knowing they could see every inch of her filled her with so much adrenaline she had to make sure she pulled her punches and didn't really hit anyone. Davis said it wasn't the first time she'd performed stark naked for a movie. She was also totally nude filming a scene in the horror comedy Freaks of Nature (2015) where she had to walk nude down a street with two male actors who were also naked. She said the two guys wore modesty garments over their penises but she went full nude. She was never shy.
James Cameron considers the film to be a direct sequel to his own films Terminator (1984) and Terminator 2 : Le Jugement dernier (1991). He was not involved in Terminator 3 : Le Soulèvement des machines (2003), Terminator Renaissance (2009) and Terminator Genisys (2015), so Terminator: Dark Fate disregards the events of these films, as well as the short-lived TV series Terminator: Les chroniques de Sarah Connor (2008). In 2017, Cameron commented that while he was generally supportive of those films due to his close friendship with Arnold Schwarzenegger, he was ultimately unsatisfied with them, so when he was invited to work on a reboot, he accepted so he could produce a proper sequel himself. He described Rise of the Machines, Salvation, Genisys and Sarah Connor Chronicles "a bad dream [o]r an alternate timeline, which is permissible in our multi-verse."
Producer and series creator James Cameron has stated that he was involved in the movie's writing, but didn't interfere with Tim Miller's direction, and never visited the set (being busy filming Avatar : La Voie de l'eau (2022) himself). He did admit that the script "wasn't where it should have been" when filming started, so he would do rewrites and send these over, sometimes only one day before the altered scenes were scheduled to be filmed. Also, after Miller's preferred cut of the movie, Cameron stepped in for some uncredited editing (as he is an accomplished editor), finding Miller's version to be "pretty rough [and] pretty long". He admitted that he and Miller had their share of disagreements, which at times "became a bloodbath. And the blood is still being scrubbed off the walls from those creative battles. This is a film that was forged in fire. But that's the creative process, right?" Miller, in turn, acknowledged the behind-the-scenes disagreements, but stated that many of these came down to "stuff that I had cut that [Cameron] thought was important", and "small lines that I saw as "poetic and beautiful" but which he didn't care for". Miller also said that although he maintained a good relationship with Cameron, he preferred to have more control on his next projects, and would be unlikely to work with him again.