You seem to misunderstand the claim being made. The article is stating that Blinken was involved in creating the policy that said Israel had the right to fire on anyone they deemed to have been compromised by Hamas. Blinken absolutely was involved in drafting and approving that policy.
After the multiple humanitarian aid bombings conducted by the IDF, Israeli politicians have been claiming that they've just been setting forth the policy agreed to by Blinken and the US. And there has been no evidence that Blinken or the US government as a whole has pushed back on that or changed their stance on the policy in question in the months since.
It's right there in the article.
Then later on it says:
Further on regarding the WCK strike: