I do realize that HP in general isn't quite as shiny as it used to be even though there are still new people coming in. I think depending on how they play that death scene there actually could be a burst of creativity before a slow but steady decline.
What I think is most important from my perspective is that we Snarry fen maintain a positive attitude. Sure, it breaks my heart every time an author/artist leaves us whether for a different HP ship, a different fandom, or original fic. BUT I know there are still loyal fans that want to keep reading and writing, creating gorgeous pieces of art or cracktastic crafts.
Maybe we'll get fewer comments and fewer entries in fests but that doesn't have to mean we're sitting and waiting for the ship to die. We just need to adapt as we have every time a new piece of canon threw a spanner in the works. ;)