I'm wondering the same thing. Wikipedia page isn't updated, I don't see any updates on https://www.mitnicksecurity.com/ or https://www.knowbe4.com/, and I can't find any other news mentions about this.

I also can't find mention of him having pancreatic cancer, but that's not necessarily a confirmation of anything. He certainly could have kept it private.

KnowBe4 has confirmed. https://web.archive.org/web/20230720043020/https://www.nytim...

Yeah seems like it was something he kept hush hush.

Sad to hear the news :\