Re: I think I figured out who Sasuke will meet
The only people able to know the truth MIGHT be:
Under his reign the massacre occured, he wasn't against the uchiha. Might be him ?
obviously, enough theories about
little information is known about him
Brother of madara, was said to have died, and dont think its him
Itachi & Sasuske's father, he should know a lot, he was leader of the Uchiha clan soooo...
So to me Hiruzen, Fugaku and Kagami are most likely.
But i like your deduction
Update: Forgot that 'them' was obviously stated, so maybe it is Fugaku and his wife Mikoto.