Terminator Genisys Ending: What Does It Really Mean?

So, What's The Terminator Timeline Now?

The best way to look at the timeline of the original Terminator is as a loop - Skynet sends a Terminator back in time to stop the birth of John Connor, but in doing so leads to Kyle Reese actually fathering the leader. The later movies add more ambiguity to the mechanics, but that Grandfather paradox is the general idea. Genisys jumps off from that flat circle, with some unclear force (we'll get into what it could be later) altering the timeline by sending Terminators back to an earlier point, 1973, which sends everything in a different direction. In 1973, a Terminator tries to kill Sarah as a child and she meets Pops. This creates a new timeline. In 1984, Kyle Reese travels back in time, meets Sarah, and they plan to go to 2017. In 1997, the original date of Judgement Day, nothing happens. Then, in 2017, they avert the new Judgement Day. The important thing to take from this, however, is that each timeline functions independently of the others, almost like a different dimension - travelling back doesn't erase the future, but make a new, different one. The other futures still exist in an alternate universe, which is how Kyle and John can jump from one to another, and also how Kyle can get visions/memories from another version of himself - it's travel in time and reality.