You could always argue that this would be so cliche that Kishi will definitely not use it.
Vader was Luke's dad. After that there's almost no way you can use that move again.
And in FFX the main villain was the main characters dad also.
Long story short, I seriously hope Kishi won't do it.
Kishi made it clear several times that the "will of fire", that the konoha people have, is so important.
And what Yondaime did is a big part of what build that "will of fire".
It would be a huge crush for the spirit of Konoha if the biggest hero was such a selfish idiot and no hero at all.
Besides, I don't really get why he would be.
He was Hokage of the best shinobi village and didn't need to worry about money.
There isn't really a point in becoming AL if the plan he mentioned is really true.
It would basically mean he faked his death to gain something he already had in the first place.
"For Feanor was made the mightiest in all parts of body and mind, in valour, in endurance, in beauty, in understanding, in skill, in strength and subtlety alike, of all the Children of Illuvatar, and a bright flame was in him"