Arnold's assertion that Roddenberry was offended by the assertion in the prologue to The Romulan Way that though the Rihannsu were many things "they were never Romulans" confuses me. What there was to be offended by?
The main/first sticking point, which brought the Duane "Rihannsu" books to GR's attention was when a fan-run convention flier made its way to the Star Trek Office at Paramount and the organizers were promoting their GoH, Diane Duane, as "Creator of the Rihannsu". She wasn't calling herself this, of course; it was a convention that decided to promote her this way.
Richard Arnold started saying at conventions (paraphrasing), "Who does she think she is? In the episode, they actually say, 'We are Romulans!'
and Diane Duane had no right to speculate otherwise."
Of course, Duane's explanation actually made more sense. That Earth people possibly branded the (till-then-unseen) aliens "Romulans" because they'd already catalogued their twin planets as "Romulus" and "Remus".