Jason Weaver almost provided the voice acting for young Simb

[Elton John]

https://www.complex.com/pop-culture/2019/08/jason-weaver-explains-why-he-was-only-young-simbas-singing-voice

Jason Weaver provided young simbas singing voice and almost his regular voice as well. Disney almost went with him but they already signed up Jonathan Taylor Thomas.

[TheLionPrince]

That's a cool story. I personally loved Jonathan Taylor Thomas as young Simba since he captured that cocky, arrogant side of young Simba. However, with today's audio technology, it's easy to hear a disconnect between Thomas's voice and Jason Weaver's voice. It would have been better if it was all done by one actor, but I'm happy with how things worked out.

On another note, the original directors revealed at the premiere of the 2019 remake that they wanted Malcolm Jamal-Warner (Theo from The Cosby Show) to play adult Simba.

[Panpardus]

I was just about to write a post about both of those things. That would've been an interesting alternative reality if both ended up getting the respective roles.