igor is probably not coming back, due to his japanese va's passing.
Yes, because it's impossible to get a new voice actor when the previous one has died. I mean, Morikawa took over for Shiozawa, not because Shiozawa died, but because he liked the Dhaos character so much and he really wanted to voice him. Same with Totani being replaced by Nakata.
In terms of Persona 5, I wouldn't mind if older versions of the Persona 4 characters appeared. But not the Persona 3 ones. They seem to have no depth, no real personality behind them, they are just there and fulfill the stereotypes of "mentor" and "upperclassmen/classmate" and nothing else.
Older Nanako? Eh, maybe...
didn't atlus say that to respect his work, they weren't going to get a new Igor voice actor?