Brian Earl Spilner said:
Confirmed cast so far:
Mufasa - James Earl Jones
Simba - Donald Glover
Timon - Billy Eichner
Pumba - Seth Rogen
Zazu - John Oliver
According to IMDB
Scar - Chiwetel Ejiofor
Rafiki - John Kani
I like Ejiofor, but Irons was so good in that role I'm surprised they would go elsewhere.
It will also seem weird if James Earl Jones is the only returning voice.