(My apologies for not knowing their stage names, if they have any. I’ll refer to them by the section they lead)
Twice when the Warthog section leader was missing, the giraffe section leader took over her songs (notably Circle of Life). Can You Feel The Love Tonight was a solo by the lion section leader, which was interesting because the Giraffe section leader was still there who usually does the duet to my knowledge. Was interesting to hear the Giraffe section leader sing the Circle of Life, as she seemed to try and sing it low(er) the first time and then sang in a higher pitch the second time which seemed more natural and comfortable for her.
Once I saw the Giraffe section leader missing, which was just as you mentioned. Can You Feel The Love Tonight became a solo with the guy covering.
As for sections when the Warthog section leader was missing, once I think I saw the Lion section leader lead both the lions and the warthogs, with a similar spiel at the beginning. The other time I saw the elephant section leader lead both the elephants and the warthogs. Could have also been the Elephant section leader leading both times, don’t remember super well.
I believe when the giraffe section leader was missing the giraffe section was lead by the lion section leader.
Anyways, sorry for the rambling, but the “B-mode” is pretty interesting to see, especially considering how rare it is to see.