Actually, the lore reason for downtime was the maintenance and reset of our NEOCOMs. This is explicitly mentioned in the Empyrean Age. I’ll put a spoiler alert at the bottom of this post that covers that.
Edit: I fumbled this. What I was trying to say is that the exact moment the NEOCOM went down in the Empyrean Age novel is the exact in-game time our NEOCOM/EVE went offline for maintenance. What was “explicitly stated” in the novel and the news articles I linked are the time frame it was down for which is our server reset window.
My ‘head-canon’ explanation for asteroids is that as our NEOCOMs go down and the in-game fictional ‘survey report’ is published, when our NEOCOMS come back online, we now have access to all the new survey information which includes sites, belts, etc. The only reason we see them in the exact same location, which is the tough one to explain, is because the game mechanics don’t allow for too much moving about. All celestial objects in EVE are static; planets don’t orbit anything, stars don’t move relative to each other, asteroid belts don’t orbit anything. So there isn’t much you can do to explain this particular issue. I guess you have to pretend they are orbiting and you’re not in the exact same position. You’re slightly off-set.
Spoiler Alert for Empyrean Age Novel:
In the Empyrean Age novel, two empires make large scale attacks/invasions and half the reason they are able to take the initiative is because capsuleers are unable to respond during the 1 hour NEOCOM downtime. It was 1 hour as at the time the novel was written the servers never came back online as fast as they do now. Especially when an expansion pack was deployed to the server, as was this particular case.