No idea where I read it but a few weeks ago I saw a site saying the studio was allegedly in talks with The Rock to play a Terminator with Arnie playing a human role as an old codger based in the 50s or 60s and allegedly that would be where they got the model design for the Terminator from. With the origin of the Terminator being a deleted scene they don't even need to retcon that officially.
It was so completely out of nowhere I presumed (and still do) it was bullshit but damn, that would be a hell of a ride.
There's a rather decent trilogy of books set after the first two Terminator movies that explores something similar, John and Sarah encounter the human original who obviously spooks the shit out of them for a start and it carries on with them teaming up against what Skynet can throw at them.