I think having a limited series for these types of books are the way to go to prevent any long-term damage to the brand, if we're concerned about that. Honestly, I'd be hesitant to even make them 6-issue series. I'd make 3-issues the typical standard, and if the book/story requires it they can request to make it into a 6-issue series.
I'd imagine an introspective book with Wonder Woman could end on a conflicted note for her or end it with uncertainty because she may never know what the perfect balance or position she should have in Man's World as an Amazon, hero, champion of women, etc.