I think that it is reasonable to expect one's partner to be free to talk about whatever they're doing with other partners. It changes things a bit when people are using your openness to spy on you. I think when you openly agree to having multiple partners, you should also feel comfortable talking about each other, with each other, as long as there is mutual respect. Keeping secrets is usually more painful than the information that is being kept secret, imo.
What about consideration for the other person? Not everyone in open relationships believes in full disclosure. In fact, in my case, I prefer some discretion. It makes the relationship feel private. This concept of the primaries having full rights removes the privacy rights of the secondaries. At least, that's how it feels to me when reading it.
Sometimes there is far too much openness in an open relationship.
In this case, we are talking about sex. Why does my wife need to know how I have sex with other people, or visa versa? There is 0 reason for that to be discussed, UNLESS it's within the confines of the sexual fantasy aspect within non-monogamy.