I don’t know why this is happening, but now twice in two days I’ve listened to a song on Youtube, clicked on the Amazon link that some of them have, only to end up with a different song by the same name. Yes, it is my own fucking fault for not listening to the sample first at Amazon, but is this something that the person who uploaded the video is malevolently doing, or does some bot somewhere slap the Amazon link onto the video, not realizing (of course) that it is the wrong song? Not sure who to complain to, in other words.
I’ll point you to the OP of this (mostly unrelated) Pit thread to see how that stuff works on Youtube.
Quick answer: Yes, the link was most likely added automatically by Youtube, not someone trying to pull one over on you.