In a sense, it was Charlie himself that started the rumors about Israel.
On August 13, Harrison Smith of Infowars made the following post (Interesting that it's about Nick Fuentes, btw):
The post resurfaced right after the assassination, and when Owens, Kelly and Carlson (people very close to Charlie) started talking about his jewish donors that went against him and started threatening him for changing his stance towards Israel, it was seen as corroboration.
Then yesterday, Harrison Smith posted the following:
Given that the official story about the murder is full of holes, people are justified to be looking into a deeper conspiracy and contemplating that some Israel/deep state related function might have taken Charlie out. Netanyahu's insistence that Israel had nothing to do with it, or his lies about how Charlie felt about Israel just before his death, only adds to the suspicions.
So far, I didn't see anyone say, "Surely, Israel was behind this murder", but if anyone has an inkling of history, the capabilities of Mossad and their implication in the assassinations of US political figures, the suspicion is a sane and logical one. And for Nick Fuentes, of all people, to not only vehemently refute any suspicion that Israel might be behind it (just like Bibi, funnily enough) but to attack anyone raising this suspicion as a possibility, tells me that maybe my previously mentioned impression might have been correct.
I was telling some friends recently, half jocking and half serious, that, whether he knows it or not, he is being funded by Zionists

or it's his psychological issues getting in the way:
He probably has so much animosity for Candace and Tucker that he refuses to take their side, no matter how much their side is the right one.
or, he got the memo.