There seems to be arguments for both sides, but still for me there is enough evidence, that there is more to this than an independent title.
1. All we have about this Hasan guy is one picture only. I would assume as a CEO with a company of more than 50 people, you would have at least some media presence or some old recordings.
2. First he gets a PS blog for his game, which is already a nearly impossible task for a developer with nothing essential in their past, but then they intentionally fuel the silent hill rumors with their tweet, which would certainly not be received well by Sony and I am sure they don't want to damage this relationship.
3. Okay more than 50 employees but with no social presence as well? Last time I have heard, the Netherlands seem to have internet.
4. Long relationship with Sony? How, why, for what?
5. A PlayStation 5 app? I would assume it would take a developer with more experience to come up with something revolutionary like this?
6. They delay the app for 3 days due to localization delays? First of all a small new developer would probably satisfied to have the thing running in one language. I am not familiar how you get an app to the Sony store, but I would assume you need to send it to Sony and they will check it (and any revisions) before it gets approved. So 3 days seems much too short for this.
7. Geoff was clearly not telling the whole story and lied intentionally with his direct message photo, where there was no answer yet to the inquiry and also no date, which means he would have needed to take the photo shortly after receiving the question about promoting the game. I don't know about you, but I normally don't take photos of messages which I receive...
He later distanced himself from the whole thing, but I mean what should he have said? How could he continue with not revealing anything?
Additionally, just imagine you manage to have some kind of Geoff for promoting your game, would you also like to damage this relationship by promising photos but then send nothing? Hell if I would have said to Geoff I will send pictures, I couldn't sleep anymore before the pictures have been sent.
8. All the people who supposedly spoke to Hasan have no real evidence about their conversation. Even if they spoke to someone, that could have been again an actor or stand in.
9. Hasan is delusional and believes that he lives in Japan and therefore is active during the day in Japan.
So this is either a big troll and this is a big well known company (probably Kojima productions knowing his history) or Hasan is a CEO with a god complex, who believes that relationships are not worth anything.