For the series to return sega must first start raking in big profits because its a very risky project that can lead to massive money losses if it flops again, and tanks to sammys pachinko divisions and the arcades in Japan they are a long way from that at the moment
I think shenmue 3 will appear some day (it was planned for the xbox but was canned due to poor sales of shenmue 2 and the console being a flop in Japan ) but not in the coming years if it happens it will be at the end of this generation or at the end of the next







