Solbor's Blood wrote:
Star Trek Phase II is a fan series.
There was going to be a "real" Star Trek Phase II series, but that got turned into Star Trek, the Motion Picture. There has never been a canon Star Trek Phase II.
I'm certainly not claiming the work done on the 1970s Phase II series is canonical. Nonetheless, it is more authoritative than novels. There was a chance that those stories would have been produced. Instead of a film in which Ilia was turned into a piece of bio-machinery, we would have been exposed to numerous episodes in which Ilia's sexuality was a constantly source of personal conflict. On the one hand, the Phase II development ideas, scripts et al, are the only indications about how themes related to Deltans would have developed: they have never been overwritten by future stories in any series. On the other, the scripts and other development material was never given a full vetting, meaning that those materials can only suggest where the production team intended
to go with Ilia. It's not perfect, but given we have nothing else to go on with Deltans ...
Unmade episodes are not canon. They can be used as a guide to see how the producers were thinking that the show could go, but very often such early ideas get ignored. For example, the Voyager Bible says that B'elanna and Tuvok have a close relationship because he is one of the few people who can calm her aggressive Klingon temperament. If Voyager had been cancelled after a few episodes, we'd be saying that this was how it was, but the way the series went is very different.