For the audience they are trying to convince, unfortunately yes.
yup and even if the Arab leaders know it wasn't Israel, they aren't going to spend political capital (even autocrats have to worry about that) convincing their population of it without the most absolute concrete unimpeachable proof available
Yes, if we have it, now is the time to use it. Biden's use of declassified intelligence pre-Ukraine war was brilliant.
Unfortunately I can also see the scenario that no matter what proof gets furnished Arab leaders won't come back to the table even though as
@Roller already said the people who get hurt most by the lack of dialogue are the Palestinians in Gaza. They don't even want to be seen in the same room as someone, us, who is also talking to Israel separately, even though, again, the most direct beneficiaries of such talks would be the Palestinians.