For what’s it worth, I would like to see CalyxOS listed if it qualifies. @jonah’s point about referencing a qualifying OS as long as it’s not worse than the AOSP is a good rule of thumb. By not recommending an option, especially when so few options exist, the implication is that the one that’s mentioned is not private enough to be trusted. Instead of interpreting Privacy Guides as being the best options that exist, it can be interpreted as being the only options that one should consider.
To the argument of not wanting to bog down users with too many choices, that doesn’t seem to be bogging down other pages that may list several options to consider. Also, I don’t think increasing the number of options from two to three is going to add too much analysis paralysis.
But also it seems to hinge on whether the the security updates keeping coming at a good rate.