Not only that, but he has enough clout that he can usually convince GOG to put whatever game he's reviewing on sale when his video comes out. He's a great channel to follow for patient gamers.
To add to OP's comment: reviews are not only a means to form an opinion on wether to buy an upcoming title.
Yeah, the game might be older, but there are still people out there who have not played it. But that's beside the point - I, for example, watch this channel because I'm interested in Mandalore's opinion, his take on a game. I have absolutely played A Machine for Pigs back in the day (and found it mediocre compared to the actual Frictional Games titles), so watching the video is akin to talking to a friend over a drink: "hey, remember xyz? that was a (great | crappy | forgettable) game..."
This kind of content might take me back to a game I haven't played in ages and makes me mentally engage with the title again - or it might put the spotlight on an obscure title few have ever heard of, or a rare forgotten gem that somehow was overlooked.
Many players do not have a desire to only play the latest and newest games, but actively look for older titles, maybe due to nostalgia, maybe due to the games having a different focus, structure etc. back then. Not saying that "everything was better" in the olden days, but different strokes for different folks, right.
That's true, I've not come across anything like this with reviews many years later, just retrospectives in EDGE and stuff like that. I'm a fan of the Chinese Room and own the game, but I've not played it before. I'll check the video later, least of all as I've been playing a lot more indie (and older) stuff of late.
I get your point but you've got it backwards imo. Detailed reviews come out whenever, especially if it's a single guy doing all the work. Pre-release reviews are, at best, rushed (very few publishers will give review keys more than two weeks before release, and you usually have several releases to cover each week), and at worse, more or less dictated by the publisher (lest your publication get blacklisted and you never get a pre release key from that publisher ever again).