So, we all agree to some degree that madara had foreknowledge of obito? If not that then his network of zetsu fished up an interesting scenario with an uchiha involved and madara, having been informed of what was unfolding, acted quickly to secure a golden opportunity. I would hope that most of us lean to madara having greater foreknowledge than just what he fishes in the zetsu network.

I personally believe that since the manga already shows a prophetic bent to the nature and reason for certain characters, stresses destiny through the words if villains which are delivered with certainty and clarity.. i would like to believe that madara, the greatest uchiha thus far and supreme master of sharingan and deliberate activator of rinnegan, madara is aware of flows and forces which reveal futures and spell out fragments of destiny. Given just how deeply the sharingan is rooted in the fabrics of illusion and reality and rinnegan the force of "chosen" elite of destiny.. madara can discern more than anyone else the future and probably even influence it to some degree beyond standard cause and effect.

Funny thing, though, the single sharingan he had after telling obito of passing on his rinnegan ... it would be unusual for him to only have one eye because there is nothing known about the uchiha of that period nor is there a tale of a stolen sharingan outside itachi's lecture of generalities concerning the clan's bloody obsession with EMS. i wouldn't call it far-fetched for madara's post rinnegan sharingan to be linked to him knowing of obito or attracting him mysteriously to the "stage" when becoming crushed by rocks. Did madara use the other right socket sharingan to guarantee obito's arrival at the cost of its light? The senju juice that is supposed to balance the toll would have been engaging the mazou anyway so it gives us room to think even a spare sharingan used by madara could wilt under forbidden tech.