^ IIRC, the main reason these Genisys movies are even being made is so the current rights holders can make as many Terminator films as they can before control reverts back to James Cameron.
And once that happens, I envision yet ANOTHER reboot...
Sure the point of holding the rights is to make a profit...
Jim Cameron doesn't need to make a profit. His estimated net worth is about $900 million. He's directed the two highest-grossing films of all time and he's working on 4 more Avatar films and a theme park for such, which'll make him even more 100's of millions (or billions).
Also, he has been repeatedly offered full control over Terminator since the mid-90s, after he lost the rights, and though he's debated it with himself, he's ultimately refused to take the controls back every time offered - mid 90s, early 00s, and just recently.
My gut tells me if TG bombs, once the rights go back to Cameron in 2019, that'll be all she wrote for Terminator for at least another 20 years. The only time I can see the rights getting back into play is after Cameron has passed and/or if a miracle happened and he got an undeniable itch in his brain to go back to it again.