Re: Reconstuction Of Fallen Stars
It's quite interesting, because originally -- according to his story-arc notes for the series -- JMS intended the Earth Civil War storyline to carry over three or four episodes into season five; the fourth season was intended to conclude with the episode Intersections in Real Time (presumably with two or three "expansionary" episodes beforehand, fleshing it out a bit more).
When season five appeared to be dead in the water early in 1997, he pulled out several of the storylines he had planned in the midst of the civil war plotline (according to an interview in early 1998, there were to have been episodes resolving the rift between Sheridan and Garibaldi, as well as a jettisoned subplot dealing with Marcus and Franklin, along with a larger number of battles), and moved everything backwards to finish out in year four. Sleeping in Light was written and filmed as the potential season AND series conclusion -- if word came that season five was a "go," he'd pull SiL back until the following year and shoot a new season finale; if not, SiL would stand as the series capstone.
The episode itself (Deconstruction) is quite well done, considering it was created almost after-the-fact, and I particularly appreciate the homage to A Canticle for Leibowitz in the post-holocaust section of the episode.
But, to answer your original question...Sleeping in Light was always intended to stand as the "final" story in the entire saga, its actual chronological placement notwithstanding.