Ending theory, or maybe red herring ending

My partner thought of this the other day… I don’t know if I would want this as an actual ending (it’s kind of cliché ie; the snow globe for Saint elsewhere or the “it was just a dream!” of the I shot JR plotline in Dallas), but what if the situation and story was actually just a D&D game the boys were playing in high school or as young adults? Even if it’s just a dream sequence, it’s a way to bring back some of the dead/gone characters. It also addresses the aged actors.

As I said, it’s too cliché for an ending, and even as a dream sequence type (Vecna is projecting or manipulating someone’s mind, maybe), but I’m wondering if it could be done well and with a more interesting twist than the way that kind of device is usually used.