Yes, I agree with your take on this.
The answers that she gave during the interview were intended to inform those interested in her particular philosophy.
In contrast...
Some situations in the book were included, I believe, to make her book more readable. A dissertation on Objectivism would have been rather dry reading. Not being an expert on Ayn Rand, I think that she understood that writing fiction was an effective way to explain her philosophy to the masses.
I discussed this earlier in another post. I decided that I was taking AS too literally because of my expectations. Since then I have decided to read for pleasure and not get caught up in the details. After all, Rand must have come to a similar decision when she decided to write fiction. She does a credible job translating her philosophy based on 'A is A' into the 'A is ?' of her intended readership.
Ping to Chapter 5.