The officials said the U.SS worried that Israel might assassinate Mohammad Bagher Ghalibaf, the Iranian parliamentary speaker who is leading negotiations with the US, or Foreign Minister Abbas Araghchi, who has also been a public face of the talks. The warnings were communicated through intermediaries, the officials said.
I agree, but I don’t see any advantage to the US warning Iran about Israel here. I’m not entirely sure what Iran could even do with this information, so it’s interesting (if true) that the US would say anything at all.