Terminator beliefs

It's funny how all the characters of the first Terminator movie (Skynet included?) believe they can produce Grandfather paradoxes while their fictional movieverse is Novikov self-consistent: not only actions that could change the future have 0 probability, but also and more importantly, all the actions taking place in the supposedly modified timeline are actually necessary for the Terminator's timeline to exist. Hadn't the Terminator gone back to 1984 he nor Skynet wouldn't have existed. The mind behind time travel wouldn't be there nor the motive to invent it for: without the Terminator's intervention Sarah wouldn't have raised John to be the leader of the resistance nor had she told him about Kyle Reese, thus preventing his birth. Even minor eventualities, like taking a photograph, had an absolute probability of 1. One is left to wonder then if Skynet is acting naively or it's actually producing a closed timeline loop that yields its own existence. Any mind that sees humans as the cause of all problems probably knows the past is there to stay.