To me it's about the band and ties perfectly with the themes in the album, but it's more open to interpretation than the others, so I understand why it's a bonus track.

I can totally see why you might think it's about Richie though. In that case I'd see it more as a lament than a jab at him

I don't take it literally about a person, or about the real death of somebody, I see as a state of mind, mourning something that died and will never come back (the band as it was)