Electric Light Orchestra
Missing Members: Drummer Bev Bevan and everyone else besides Jeff Lynne and Richard Tandy, 2014 to the present.
Background: Jeff Lynne pulled the plug on Electric Light Orchestra in 1986 to focus on his career as a producer. What happened afterwards is so complicated it would require an hour-long PowerPoint presentation, but the short of it is that drummer Bev Bevan put together a new project called ELO Part II with other ex-members of the group. A lawsuit was filed. When all was said and done, Bevan moved on with his career, but other former ELO/ELO II members tour to this day as the Orchestra. Lynn, meanwhile, revived the group as Jeff Lynne's ELO in 2014 for a new album and a series of tours. The only member of the old group he brought back is keyboardist Richard Tandy, though he's had to miss some recent shows due to health problems.
Impact on Reunion: None. ELO has been Jeff Lynne's band ever since co-founder Roy Wood walked away in 1972. He writes the songs, plays many of the instruments and produces the albums. Fans flock to Wembley Stadium to hear him sing the material decades later. If Bev Bevan isn't on drums or Mik Kaminski is not on violin, very few of them know or care. A tiny hardcore fan base may fixate on such matters, but they still buy the tickets.
Odds of a True Reunion: Would a negative number make any sense in this context? Jeff Lynne hasn't spoken to Bev Bevan in decades. The drummer didn't even show up when the group was inducted into the Rock and Roll Hall of Fame. Other former members continue to tour as the Orchestra, annoying Lynne to no end. There is not even the tiniest of tiny chances he's going to bring these people back into the group.