G/M seem to get a lot of things wrong. It seems too that when Simson doesn't have a fact to fill a gap, he just makes one up. He tried to get a job at NeXT once upon a time - they didn't like him. Whatever. I believe he also wrote the text that shipped with the OS and the press kit.
His book is just an Openstep/Cocoa update of his fomer NEXTSTEP PROGRAMMING Step One.
I've got it on my bookshelf.
No Simson didn't write the press kits for NeXT.