Hello,
No, whoever told you that is wrong. The clips will be old but not that old, like early 2000's.
They don't take up the whole screen, there's a 1-1.5 inch black border around the video but it's hardly going to affect your ability to pass this test.
The hazard perception test is backed by flawed logic so don't be surprised if you fail it first time around. If you click every time you see a potential hazard like I did then you get 0 points for that particular clip as you're apparently cheating. I was clicking every time I saw a female driver as they are potential hazards but I got 0 points because their scoring system is wrong, they design each clip so that there's only 1 hazard and they have a specific time based scoring system, if you don't click within their timeline then you get 0 points, if you're like me and spot the hazard ages beforehand then you get no points as you're apparently supposed to wait 5-10 seconds after you spot the hazard to click, somehow in real life I don't think I'd react that slowly to a real hazard.