Not sure, no one is. It is Saudi, no one ever knows what they are thinking.
Why the crack-down to begin with?
Thinking the King wants to take away power (money) from the squabblers that want his throne, and by throwing some under the bus he is causing the other 3,000 members of the Royal family to step back and stop this open wrangling over the throne before he passes.
A few high visibility arrests, some to to jail, some even may die (you won’t hear of it but the family will), and they will jump back into their box.
I think the family was openly fighting over the throne and the King had his favorite and that favorite probably was losing the struggle to get support. The King doing what he did sent a message of support for his favorite and this is important before the King dies because the family (all of them) want to be on the live King’s right side and they got the message on who they better back for succession.
Just my guess. . .
Thank you for the information, I am trying to get a better understanding and appreciate your help.