It would've been cool if they had kept the station looking like that (well, with all structural damage closed off, but the pylon still missing), or at least for a few episodes.
Indeed. Or at least mention in dialogue something about finishing repairs on the pylon.
There's another example of "magic restoration" coming up before the season's done, and while in both cases I understand not wanting to alter your sets or visuals - both from a costs point of view and from the view of not alienating viewers by changing iconic designs - it does distract a little from the emotional power of the events. I suppose it's another reminder that DS9, for all its impressive continuity and arc-based plots, still wasn't quite ready to discard the episodic format. It's nowhere near the level of "Hard Time",
of course, but the next episode definitely loses a point or two in my mind for not reinforcing the initial impact of seeing DS9 with major damage. As TheGodBen
says, it's a jaw-dropping moment, but ultimately it means nothing.