This a great example of how 'naming things' is by far and away the hardest problem in computer science. If you're going to call something 'normal form' or 'manifesto' it's best if there's exactly one of them. By the third one, others start wondering how normal the first form could have been and whether it might not have been more prudent to try a communique or memorandum before going full manifesto.

While I understand your point, it is my understanding that the first two "manifestos" weren't by Date and Darwin. I think Cobb's original article introducing the very idea of the relational model is one of them, and I forget the other.

They are rather making an egotistical (but IMHO deserved) point that their work is the 3rd revolutionary call to action in the history of relational database systems.

Yes, it's not entirely without uses to have a third manifesto. There was, for instance, a NoSQL manifesto a few years ago. Relational purists could reasonably point out this is a clear sign of the immaturity of the new technology as they were on their third manifesto nearly two decades previously.

I found some of those purists very annoying. The real world is often messy and organic, and trying to force excessive order on it just makes for confusion and/or silly extra busy-work.