Possibly. But this is the first time the Saudis have publicly and proudly offed an American citizen, without fear or reprisal, or even much of an attempt to cover it up. I mean, it was MBS's own personal security detail who did the dirty work. He WANTED the US to know who killed Kashoggi. It's not like it's hard to find someone to drive by on a scooter and shoot him, in Erdogan's Turkey. That's commonplace. And a journalist? Really? Nobody cares about journalists any more. This was MBS testing his new power, now that he has exterminated all of his siblings and cousins. He wanted to test exactly how much clout he had pooled, so he can push the Kingdom further into the future without concerns from the US, Russia, and (possibly) China. This was a message. A test. We failed.
Crappy Ed Sheeran remake of "We Didn't Start The Fire?" Sure. Historical turning point? Not a chance. 15 of 19 September 11 hijackers were Saudi and it didn't alter US foreign policy towards Saudi Arabia in the slightest. Jamal Khashoggi was a Saudi princeling whose entire career was in Saudi Arabia, other than a handful of columns for the Washington Post. Everyone involved knew he could be murdered with impunity, which is why the Turks have audio of it. Otherwise he'd be just another disappeared journalist.