It's a slightly unusual addition to this series, as nobody actually DIES in it, it's simply a really sad and plaintive song. But I like it and it's going to be included on the album anyway, so there you go.
I think a more interesting speculation about this song, and various other "pining away in anguish" type ballads, is what function they may have served for the singers and listeners. I can't find the link at the moment (I'll come back and add it in later if I can) but not too long ago I read an article about how a lot of classic country (Hank Williams Sr. etc) dealt with heartbreak and infidelity largely because it was a socially acceptable way for men to express negative emotions. It could be hard to say "I'm not sure how things are going and I have doubts about my relationship" but "I caught my wife with my best friend" is a concrete image that stands in for those other uncomfortable feelings (it's worth noting that a lot of other Country pioneers struggled with alcoholism and very likely depression, so there's that).
By the same token, I suspect that in addition to the very human fascination with crime and gory drama that murder ballads give us, these sad old songs also had another purpose as a channel for negative emotions that balladeers and audiences alike may have had a hard time putting into words. Our terminology for generalized depression is pretty new after all, but depression itself likely isn't, nor are a host of other psychological ills. However, when somebody sings about being heartbroken because their true love dumped them, most folks can relate and it gives a shape to pour those nebulous feelings into (and if you up the ante by having your love die of violence, or illness or werewolves, all the more dramatic and emotionally poignant. After all, we may not have all lost our fiancée to werewolf attack, but a lot of us have had days when we've felt like we have).
And of course, in a lot of traditional cultures, especially among men, expressing too much emotion wasn't always socially acceptable. The allowable range of emotion would probably be limited to "Angry, hungry, drunk, horny or folk song." Thus music, which on one hand has often had such a role in bringing people together in joyful dance and celebration, also served the vital function of providing an outlet for negative and hard to define feelings. I don't know that, with the ever expanding, yet still incomplete, understanding we have of the human mind nowadays that depressing music could be considered the healthiest or most effective form of therapy, but there was a time when it was all we had.
And besides, it seems to be working OK for some modern English singers.