That article is ridiculous on so many levels. It's conspiracy theory BS, nothing more.
For anyone interested in how a hotel assassination would actually go down, here's CCTV footage of the Mossad (Israeli intelligence) taking out Mahmoud al-Mabhouh, a Hamas terrorist. The location is Dubai, UAE :https://youtu.be/bJujIwtdk8w
If the Saudis were going to kill one of their own on US soil, they would do it like that. Notice how the Israelis did it quietly so they could actually flee the country without getting caught.
The Saudis would get caught. Plus, they just kidnap their misbehaving royals and fly them back on a private jet for punishment. It doesn't look as bad and the US doesn't care.