I wish it weren't true, but this is the bottom line: Some members would see revealing spouses on profiles now as a violation of their trust.
Therefore, my explanation above still stands. Putting spouses on profiles would probably require a new Privacy Level or lots of profile deletions.
Honestly, I wish this weren't true. I've been convinced that it would be better if we included spouses in the definition of "family tree". It would be more logical. It would help us be a better resource for information on notables/celebrities. It would help us perform better in search engines. It would be good for non-family collaborations. I wish this is how we had done it from the start.
Could we get away with changing it? Yes. I doubt we'd face legal consequences. As has been pointed out, our promises have been vague, poorly explained, and inconsistently applied.
Moreover, I can think of cases where other genealogy websites have pulled the rug out from under their members on privacy-related issues -- much bigger privacy issues than this -- without apparent consequences. But we don't want WikiTree to be like those other websites. It's a matter of integrity and trust. We need to try our best to uphold all implicit and explicit promises, especially concerning privacy.
So, I think we need to:
1.) Fix the privacy hole in the Connection Finder where a connection between two spouses who are Private with a Public Family Tree reveals their names. I'm not freaking out about this because I think it's a minor violation. The Connection Finder results are not indexed in Google and they're not easy to predict. They couldn't easily be used by someone who wants to discover non-public information about marriages.
2.) Make the treatment of spouses on descendant charts consistent with how spouses are treated on profiles.
3.) Create a help page explaining things and fix what it says on the edit page.
I'm sorry to say that I think #2 means removing spouse information from the descendant charts, not adding more to profiles.
At first I'd thought that we could put spouses of a Private with Public Family Tree person on their profile if the spouse is Public, like we've been doing on descendant charts. But this isn't right. The privacy level that matters is the one for the person profiled. The privacy level of a private person's spouse should be irrelevant.
I'd also thought that we could do what Ellen suggests about putting "private spouse" when we can't show the spouse. But this would be going beyond what we've done in the past. We would be revealing that there is a marriage. I know that we've been revealing it elsewhere, e.g. on descendant charts, but that doesn't make it OK for profiles.
I don't think putting "private spouse" would be logically consistent either. We'd have to put it for the public spouses. That is, in those cases where a Private with Public Family Tree person has a public spouse, we couldn't reveal the spouse but it's not because they're private, it's because we don't reveal spouses for private people.
And ... I'd also thought that maybe we could make exceptions where there are children with public family trees, where this rule seems especially absurd. That is, if spouses who are Private with a Public Family Tree have a child who is Private with Public Family Tree, why can't we reveal the marriage since we are revealing both parents on the child's profile? But revealing parents is not exactly the same as revealing a marriage between the parents.
I know this is complicated. I wish we had foreseen all the consequences and taken a simpler approach.
For what it's worth, spouses can be revealed in public biographies. Maybe it would even make sense to have a template that creates a feature box for it.
Also, I want to make clear, nothing about spousal privacy affects family trees. Fundamentally we are a family tree website.