the h*cking d*mb """administration""" (more like the oppressors of roleplay am i right) shouldnt have ever FORCED their """vision""" of a """storyline""" on us roleplayers........... it led to the DEATH of tnbs MOST BELOVED server!!! give us BACK our HL2 WITHOUT ADMINS!!!! gamers rise up!!
anyway that aside, p much what everyone else said, but with a bit more detail:
the hl2 server ended up losing population over time because there's only so much you can do with city 17 (out of all places) as setting without stepping into eyeroll-territory, and because "everything is okay" slice-of-life city-life rp is not a sustainable concept contrary to what others would want you to believe. neither is "everything is okay: forest edition", for that matter. so, it was decided to kick the server into the uprising, and to send it off with a worthy goodbye - of course we could've kept it up on life support, we could even have it up right now, but it's often better to let something go rather than to cling to it like a maniac. the server would've died anyway; the uprising story arc atleast wrapped it up and sent it off with a bang to remember as one of the coolest things tnb's done in atleast the last six years.
currently, we're even planning the continuation of this setting - a half-life 2 roleplay that takes place after the uprising. it'll be pretty neat - while hl2 was a story about overcoming burdens and working together to defeat a common enemy, a story about humanity standing at the brink of extinction, phl2 will be a story about rising from the ashes - a story about humanity entering a new era. there'll still be plenty of antagonists (the combine forces are cut off from their reinforcements, but that doesn't make them all disappear), and i'm sure people will get their city life rp fill if they desire it so much, but we're making sure the server will offer a lot more than just that.
so, tl;dr - in a way, it's being continued at a later date!