Will S&box kill gmod?

S&box is more of a standalone game rather than a sequel to Garry's Mod. Because if all players does move to S&box, what will they get during launch? It's not like there will be a Roleplay server pop up already in S&box server list, same goes for workshop addons. Without workshop, game is entirely useless. So it probably won't kill of Garry's Mod instantly, unless S&box has the stuff and content that Garry's Mod provided.