This means we're getting a new Terminator trilogy that kicks off with a future John Connor sending the original Arnold Schwarzenegger Terminator farther back in time to raise Sarah Connor (she calls him "Pops") and fight a younger T-800, which in turn creates an alternate universe. Also, Arnold will look like a 67-year-old robot,Sounds like a disaster.
I would have like to see a Terminator sequel that gave a technologically plausible rise of SkyNet. The movie could have skipped the time travel, and shown the progression to the great war between humans and machines in the future, as the Terminator movies allude.
We are seeing many AI advances coming, such as the internet of things, self-driving cars, voice-controlled agents, etc. If you believe the technological singularity seers, these and other AI advances will bring some radical changes in a couple of decades. I am not sure that they are right, but they certainly have visualized a future that is plausible enuf for a movie.
So I would show a near future where ordinary lives increasingly come under the control of machines, and people accept it. I would show some occasional machine mistakes that are also accepted. Then I would show a machine making some logical but shocking decision, such as killing an innocent baby to prevent some greater tragedy.
John Connor would see the dangers in this, and maybe commit some criminal sabotage against the machines. The machines then conspire against him. There are a lot of possibilities here.
Arnold would be an engineering genius robot designer. He would be a good guy, because he is too big a star to play bad guys anymore, but his products are programmable and some of his customer turn them into ruthless security guards, drug deals, hit men, and worse. Because he is the designer, some of the cyborgs look like younger versions of himself. This is how he can be an old guy in the movie.
It appears that the Terminator movies will do none of this. Other AI movies have been disappointments. Someone will surely make a good AI movie.