You are taking this recommendation completely out of context. This is a recommendation for confidential communications, not releasable under public record laws.

You are taking this recommendation completely out of context. This is a recommendation for confidential communications, not releasable under public record laws. But neither of those applies for the Signal chat in question. That was not confidential communication, it was top secret active military data. And, like any other military-related decision, it was very much in the category of information that must be recorded and was going to eventually be releasable under public record laws, as soon as its confidential nature expired, 50+ years from now most likely.