Your theory is interesting, but I don’t think the powers that be would let obama ever become a candidate for president under those circumstances and risk. Surely they could have groomed another clean and articulate black man in that long time period.
I do not think Obama was pre-selected or groomed to be POTUS. I think that just happened because he was a good public speaker in the Chicago machine.
Remember Jesse Jackson’s reaction to BHO’s campaign - “cut his nuts out”? Quite a few black leaders were upset that BHO jumped the gun and ran. They were hoping to have more time to clean things up.