Terminator 7 can't go back on a promise Arnold Schwarzenegger has made about the franchise's future. The Alien and Terminator franchises have a similar, James Cameron-shaped problem. The writer/director hit the ball so far out of the park with the second entries in both sagas that future filmmakers found it nearly impossible to match them. The Terminator movies, in particular, have floundered since the second film; the third outing was a big hit but far too goofy for its own good, while the most recent outing Dark Fate was a box-office bomb.
https://screenrant.com/terminator-7-arnold-schwarzenegger-not-return-promise/