They're sort of delayed because they're areas with only events and not effects - though the new Japanese Gardens have a menu in them - and that and there's a few connecting areas so coming up with the page itself is somewhat. Iffy.
First everyone needs to agree on a name, or someone goes "fuck it" and slaps a name down. Sort of like with GALAXY Town . Then usually (and by usually I mean as of recent because I'm a lazy slob) there's notes written down on the articles on the various events, effects, NPCs that react to which and what, etc.
Then people add pictures, and then there's the final cleanup. It's more like an assembly line process lately than a full on *GENERATES AN ARTICLE OUT OF NOWHERE* type process.
tl;dr it's a bigger thing than what it looks? in a sense? it's not that simple as just slammin down articles as new areas come