Lots of people said the embargo should be broken early because "the exploit is already in the wild". That does not normally mean an infosec researcher has a PoC on their private laptop, that means it has leaked, one way or another.

Had it, though? If it was in the wild at day -1, surely some script kiddie will be happy to run that exploit at day +4, because if they didn't someone else would.

There were many people saying things with great confidence and this is one interesting way to gauge what was behind those words.