CISA explicitly promoted Signal for use by top level government officials. The fact that an outsider was invited to a conversation they didn't belong in is troubling, but basically nothing else about this seems to be outside of recommended policy.
The administration is also claiming that there was no confidential information in the conversation, which I think is certainly debatable, but the rest of the story seems overblown to me.
The administration is also claiming that there was no confidential information in the conversation, which I think is certainly debatable, but the rest of the story seems overblown to me.