Hammer Ys Net, Deep Silver, Awesome Japan, etc. hard on the fan-led marketing initiative. Why would ANY company worth their salt turn down free marketing? This is the most successfully funded Kickstarter of ALL TIME due to fans.
I think it's a great that fans want be involved in spreading the word about this series. That being said, there are many reasons why companies turn down this idea of "free marketing" from fans all the time.
Marketing campaigns are carefully planned to manage expectations and build hype. People are well-paid to design these campaigns and have ownership over them. It's their career and they have chosen their own team members to execute their plans. A well-meaning fan can unintentionally disrupt the pacing of a campaign, use unapproved materials, associate with unapproved sites... there are lots of things that can go wrong, and that's with well-meaning fans.
Now think of borderline cases such as a so-called "influencer" who becomes a high-profile fan promoter of an IP, then something short-circuits in their mind and they wander into a public bathroom during a livestream, or behave as a disgusting foreigner in Japan, or some other crazy shit. Then Shenmue is associated in peoples' minds with some unfortunate, potentially illegal stunt.
Now think of a troll who plays a long game of pretending to be a fan and then at some point changes into actively attempting to damage an IP.
The company does not want to get involved with amateur marketers whose actions are unapproved and who are unaccountable if something goes wrong.
Shenmue does have a unique history of fan support, so one would think that it would make sense to reach out to fans and involve them in promotions in some way. But obviously there are also downsides to this sort of thing. I've seen a lot of salty comments directed at Adam Koralik because he was perceived to have gotten special treatment that other fans felt like they deserved.
It's just a really messy situation to go wading into with a lot of potential downsides and a very narrow potential path of success, so it makes sense that companies generally do not want to involve a bunch of extremely passionate (i.e, volatile) fans in carefully planned, extremely expensive marketing campaigns.
Edit: impenetrable wall of text organized into paragraphs at Xatruio's encouragement!