Yup. As I said before the whole beheaded babies thing is really just a distraction but it seems incredibly stupid of him to reference this at all, unless he’s working off cast iron intelligence. So stupid.
Even with cast-iron intel, you have to go through so much to verify something like this. Inquisitions, autopsies, family histories. No one is saying it didn't happen, most, if not all merely hope that, but proving it did happen this early is so far beyond the limits of what is possible (within margins of error which remove all potential for propaganda) that it is insane to speak/print it. Consider, the story gets told. It is amplified. Now, what incentive does Israel, even if it isn't true, have to walk that story back? If false, it will become evident within time (the same as if it's true). But if ambiguous or possible then Nethanhyu can say to other leaders, "we have direct reports/evidence of such a thing" based on much the same levels of confidence as the reporters' who cannot, themselves, verify it. So given Israel doesn't want anything but the world's support, same with Palestinians, if it were discovered to be false, now, there is no state-incentive to immediately dispell it. Whereas within the coming days and weeks, the reality of what did (or hopefully, didn't) happen will become evident beyond all possible "mere propagandistic usage".
If not true, and I hope it isn't, Mossad/Israeli intel, can merely claim "fog of war" (and so can the US president and press associations). But that's precisely why you wouldn't repeat or print the claim. Biden doesn't have much incentive to dispell it either even if he suspects general propaganda because he has to justify American support of Israel to a divided US audience.