I used to do Middle East. Not so much anymore. I haven't followed the ins and outs of the Saudi royals either. That's its own real world. If you are interested, I can send you pointers to people who know this stuff well.
But, I do know this: every single Arab country, without exception, is built on sand. I don't mean this literally (although it seems true in many cases.) Rather, I mean that the societies are fragile, they are run by unpopular dictators, and their economies do not meet the needs of their people. All of these states (as we saw in the Arab Spring) were dry tinder waiting for a match.
I write this thinking that we need to consider seriously that the Jamal Kashoggi affair could bring down the Saudi government and replace it with a terrible civil war. The Saudis themselves are clearly concerned about this.
Smart Middle East hands, who may not like the Saudis much, will probably say we use this carefully push them towards reform - but we don't want to dump them. They are valuable allies (if morally dubious ones, but hey, welcome to the Middle East.) I don't like the Saudis much either. But, this is probably the smart play.
Putting aside this administration's competence to pull of the smart play, things can get out of hand. The opprobrium heading towards the Saudis can set a serious set of cascading events into motion. The Saudi regime cannot take care of itself. It relies heavily on foreign technical support. What happens when no one wants to provide that support because of public pressure? When the Saudi people lose confidence in their corrupt dictatorial regime, they are done for.