It'll be fine. They clearly haven't started development in earnest, extremely common in Kickstarter games where they're not sure what the response will be. There are Shenmue veterans on the team that will do everything in their power to make sure this is a Shenmue game and given how insanely positive the response has been in such a short amount of time since announcement, I'm assured that this will be the sequel we've wanted. The reaction also bodes well for the possibility of extra funding from a publisher, another common thing that happens with Kickstarter projects that are doing well.
Games take time and we're Shenmue fans, the very definition of patience. So be patient.