rfmcdpei, considering your soft-spot for the romulans and especially for the 'rihannsu' book series detailinng their culture, I think you'll be pleased to find out that RBoE integrates some information from said book series into the main continuity such as: the romulans calling themselves rihannsu; the romulan naming fetish.
Indeed, the integration intensifies ...
By the way, is that you over at Centauri Dreams?
If you're referring to the O'Neill colonies viability discussion, then yes.
It's a shame: the Ascendants really do need to be developed. And what has happened to the Dominion?
Regarding the Ascendants conflict - it's pretty certain that, at present, there are no plans to conclude the plot-line. The hints regarding the conclusion of the conflict present in RBoE are FAR too obvious.
Let's start with prophecies.
They are predictions regarding the future. When it comes to DS9's Prophets, they are accurate predictions.
But everyone even remotely familiar with ancient greek tragedies or Shakespeare's Macbet knows that there's more than that to prophecies - they're amenable to different interpretations, they're easy to misunderstand, they're tricky.
In DS9's case, this was conclusively proved by episodes like 'Destiny' or 'Favor the bold'.
My interpretation of Sisko's actions in RBoE and the prophecy 'if you marry Kassidy, you will know only sorrow' is:
Sisko, by allowing himself to be lead by fear of some prophecy, inadvertently fulfilled said prophecy, in the purest Oedipan tradition.
The sorrow Sisko caused his family is the sorrow the prophecy spoke about. And so, ironically, far from avoiding this prophecy, during RBoE, Sisko caused it to happen.