Retirements are almost always never permanent. Case in point, The Snitch. The since-retired leaker couldn't resist jumping back into the hype train to release a tease for an upcoming announcement by Sony.
Technically, The Snitch isn't the source of the leak. In their public Discord, The Snitch said that a "reliable source" has confirmed that we'll be getting more information about third-party content for the PlayStation "very soon".
Unless The Snitch is talking about an untitled PSVR 2 project, which is also possible since the upcoming VR console will come out soon, the words "3rd party stuff" for the PlayStation can only mean very few things. If we assume that it's a third-party exclusive for the PlayStation 5, it might come from one of Sony's long-time PlayStation partners, specifically, Japanese companies like Capcom, Square Enix, and Konami.
We know Square Enix is releasing two third-party PS5 exclusives with Forspoken and FF16 coming out on January 24 and June 22, respectively. Meanwhile, Capcom's Resident Evil 4 remake, which will be out on March 24, isn't a PS5 exclusive. This leaves Konami, which is currently working with Bloober Team on the Silent Hill 2 remake, among other projects.
It would make sense if The Snitch is talking about the remake of the classic survival horror game since it's said to be in the final stages of its development already. But, The Snitch would've left probably more clues if it was just talking about the Silent Hill 2 remake.
Either way, Sony is expected to hold an event sooner rather than later with a slew of exclusives coming to the PS5 in the first half of the year along with other big titles.
Hopefully, we'll know more about what The Snitch is talking about in a few weeks. Hideo Kojima's fanboys would love for the third-party title to be a Metal Gear Solid remake, as presumably alluded to by Bluepoint Games last Christmas, but it's best not to get your hopes too high up when it comes to these sorts of things.