There is no Time Travel in the Terminator Franchise
There is a trap most audiences fall for, that trap is perceiving the reality of events in a movie like the characters in the story do.
As the viewer we have the privilege to observe the events unfolding without being limited by the perception of the characters themselves, that means that sometimes we can see more than the characters do, and that goes beyond knowing the villain in a slasher movie is right around the corner while the victim doesn’t.

The Terminator franchise displays a magnificient version of this same principle but in two different ways. The standard one where we know the Terminator is right around the corner, but also the wider version where we can see the specific order of events unfolding in a movie.
In the Terminator movies we see the “future” and the “past”, and they seem to unfold parallel to each other. While that might seem ok for some, I would like to present you a new perspective. The perspective that there is no time travel in that franchise.
Don’t get me wrong, the characters do believe they are time traveling, Skynet could believe it is time traveling (it is uncertain since it is never explained beyond a date in a terminal in T:G).
The catch to finding out what is actually going on is the order certain characters show up in the movie.
The terminator (villain) arrives first in Terminator, Terminator 2: Judgement Day, Terminator 3: Rise of the Machines and arrives first twice in Terminator: Genisys.
If the franchise had any aspects of time travel and altering “the future”, that would mean the machine, even if it departed from today 5 minutes ago to this same day in the year 2000, would have had 19 years + 5 minutes to finish it’s task before any response from the resistance could even be thought of. That means it would be 100% successful, which would make it not the last resort in a war, but the first option.
The movies display both timelines as concurrent, and while that is indeed a feature of cinema to show different perspectives and sides, it also helps the narrative that both “past” and “future” are not actually linked. That could be expanded even more to say that the movies themselves display different realities.

That means that while the characters are trapped in a point of view where “time travel” happens, we as viewers can see it in a wider scope because we can see both universes developing. Terminator Genisys is one of the few movies that expanded this fact and no one seems to have noticed it.
Making John Connor into a Terminator (real or not since it could have been a shapeshifter terminator with just stolen memories) doesn’t matter into the greater scope of things because that is just one future. Kyle Reese and Sarah Connor don’t need to hook up because those versions are not the parents of “future” John Connor.
If you still need some help understanding this, maybe the best way to visualize what I am saying is imagining various dimensions\alternate universes side by side, concurrent timelines where the difference is minimal enough for humans not to know that they are not in their reality when they “time travel”, so when you “time travel” you actually go to a reality where that date is the present time.
Another evidence from that comes from Terminator: Dark Fate. (Spoilers ahead)

When a T-800 kills John Connor, but no Skynet exists in the future (as said by Grace in the movie), that means Skynet never happened in that reality but a T-800 still existed, the same T-800 that later says he is a Cyberdine model.
Preventing Skynet in T2's reality doesn’t prevent a Skynet from an alternate reality from sending terminators.
That is proof that while the destruction of Cyberdine in T2 was successful in preventing Skynet from happening, it instead was a prevention of a repetition of that specific apocalypse, they did not save “the future”, just a future, from one specific cause of an apocalypse.
(I just explained to you what probably was your biggest complaint about Dark Fate and why it is not a real problem at all)
But I could take that even further, if Skynet knew it was not time traveling, then it can be safely said it was instead spreading itself through other dimensions, making sure it is always present to retry again and again even after it loses wars.
(T1 indicates that it doesn’t even have the first Skynet, since John Connor already knows Kyle Reese is his father and the events of the first movie lead to the picture that it is taken at the end of the movie, same picture Kyle Reese carried with him in the “future”, same for T:G)

(This theory does indirectly validade all headcanons though, so I know some people could dismiss it just based on the fact they would have to live in a world where they can’t hold on to the “true canon” of the franchise…. where everything is canon… somewhere.
But that means there is a universe where only T1 and T2 happened, so that might make you more accepting of the ideas presented in this article if you are the purist type)
I hope I explained it well enough, I doubt this will get much attention but if you have questions just leave them as comments.
