So I was just thinking about it this morning.
There are massive numbers of Sin’dorei NPCs walking around this cool new city, which is great and all, but didn’t 90% of their population get decimated just 20 years ago? This place feels weirdly populated given that information.
If I’ve learned anything about this game, it’s that population numbers only matter when they’re convenient. I suppose there could be an in-universe explanation as well, perhaps it would’ve been even more densely populated at its height. Alternatively, perhaps the majority of depicted citizenry are of a new generation; two decades is about enough for that, plus there’s plenty of children around. It’s far easier to assume the former, however. Obviously Silvermoon would be significantly less impressive with less npcs milling about. Personally, for the record, I didn’t really think Silvermoon was that crowded. As the political center of their nation, it should contain the highest concentration of their people.
I didn’t feel it was ‘overpopulated’. You also have to remember TBC apparently took place 41 years ago and the elves live for thousands of years. To think none of them had offspring or that the remaining adults from other places did not converge in the restored city is a bit silly. We saw plenty of elves outside of Silvermoon and even Azeroth in TBC.
Friendly correction: TBC was not 41 years ago. It happened in year 20, and we are currently in year 43ish. Anduin was alive, and still a child. Arator is not that much older than he is. This is all still very recent history. Theoretically we can have more population, but it’s going to be a very young population, otherwise the math ain’t mathin’. 
Oops, Aran on an alt. Hah. Forgot to swap.
You’ve never been in a real city, have you? To me, Silvermoon looks pretty depopulated.
would downvote if i could, no need to be rude.
OOC explanation; I think it’s just that processors and graphics cards have gotten better so blizz is pushing to make in game representations more accurate. If you look at estimates population numbers by lore they are never accurately represented in game. I think it’s just a iterative step towards a more lore accurate world.
For the sake of my sanity, I’d like to believe that the Blood Elves were able to rebuild their population to the point where they’re on par with secondary cities like Mulgore or Suramar, and that the Blood Elf population is no longer on the brink of extinction. If they’ve managed to come up with excuses for the Death Scar healing by magic and for many other inconsistencies in the story becoming coherent, then this doesn’t have to be an exception.
Even if you went and counted every NPC, it’s still not that many people. Obviously, real numbers don’t really matter, it’s just a representation. But I disagree that it looks too populated.
My head canon is that there was a baby boom afterward so you have a lot of young adult elves walking around.
This is my headcanon as well. Especially now that Silvermoon has a fairly active and (most likely) overwhelmed daycare center. Which should also allude to the idea that Silvermoon has multiple daycare centers throughout the city
You also don’t go around repopulating destroyed towns without having a fairly massive population boom as well.