There isn't a spoiler warning big enough. They're planning to show this thing on TV?
The idea that John Connor himself has turned into some kind of Terminator is the sort of brilliantly dumb idea that you get when a franchise has been all but used up, and here we are. I'm not sure what to think about this, outside of being annoyed that such a huge plot point has been given away during the film's second trailer.
This might have been a really cool moment in the theater, but now it's going to be picked apart long before the movie opens. This isn't anything new for the Terminator series, as the trailers for Terminator 2 gave away the surprising fact that the Terminator was more or less a "good guy" in that movie, and this latest film is also making sure there won't be any surprises left by the time it's released.
To be fair, the plot was already pretty silly.