I think it's questionable based on a few factors.
We already know that no one was fronting the cash for SIII for a long time. It was thanks to the Kickstarter that it even happened, otherwise, if not for that KS, III would not have been. No one was fronting the cash until we fronted the cash ourselves to show there was interest.
The reason I think SIV is gonna be a harder sell boils down to the fact that there is no KS to help it out this time. Leading to the question that lingers; who's ponying the cash for Shenmue IV? Who's gonna pony up the money especially considering the lukewarm reception to SIII from both fans, gamers and press alike? The game didn't exactly sell like hot cakes on release. Hell, within the month of release, the price was knocked down to try and entice sales.
I think based on that, it's gonna be a hard sell for any publisher to front the cash for a game that may not return their investment. I fear it's back to square one.
I'm not saying it's not gonna happen. Certainly there is a flip side to the argument that the game had already made $6 million in its KS state proving the fanbase was more than willing to pony up the cash to make it happen and that could play in favor for someone to put the money down and make Shenmue IV. But at the same time, it presumably cost somewhere around $20 million to make Shenmue III as is. (? -- not sure about the actual number but that was the last I heard).
Now granted, I don't know how many copies of Shenmue III have been sold nor do I know if it even made a profit or is still in the red trying to recover its losses, but it is something to take into note when considering "who's gonna pony up the cash to make it happen?"
The reason I say its a harder sell than SIII is because SIII at least had the KS to show there was interest and get further investment...but I worry if they can investment for SIV based on the somewhat lukewarm reception that SIII had. I just think it's gonna be another battle.
But I certainly don't want to lose hope. Like I said, SIII happened against all hopes so I certainly haven't given up hope in SIV happening. The tools are certainly there. They have the systems and assets built and ready to be further expanded on. I think SIV could be something awesome now that they have their heads wrapped around Unreal and have the tools in place to do more with it.
I just hope someone is willing to pony up the cash to make it happen but based on the sales and reception of SIII, I just think it's gonna be a hard sell.
But we will see...you can't discredit the interest in the series is still here and maybe the sales of SIII aren't as bad as I fear and hopefully someone is willing to invest in another game. I mean I'm hoping it happens. I certainly want SIV to happen.