> unknown if they participated
There's clear public footage of Faisal Ali Musalam Naami (UNRWA employee) participating, at least. The Telegram chats also show widespread support for Oct 7 and other overt antisemitism - https://unwatch.org/wp-content/uploads/2024/01/UN-Watch-UNRW...
You can UNRWA is just one small part of the UN, but so was the commission of inquiry behind the genocide accusation, which consisted of 3 individuals with some questionable backgrounds.
> arrest warrants from the ICC
Why would Israel hand anyone over to a court whose jurisdiction it never consented to?