Good chance like with other AAA devs (current or not) they already had the work going but the kickstarter is the extra push/interest basically. So while the funds obviously help, realistically no one will fund a 70-227m+ project. Shenmue III long as more than likely been in production and just on the back burner since iirc they developed all 3 games KIND of at the same time so they kept the flow properly going. But we know the history.
I still remember waking up that Xmas morning to bust out Shenmue I and going through that 3 disk game. Didn't have that much excitement or anything until FFIX came out.