This could potentially be the case, Madara might be acting to draw out Sasuke's full power.
It could be that:
EMS + Senju DNA + Near death experience = Rinnegan
EMS + Near death experience = Elder Son's Doujutsu
Though personally I believe that Senjutsu has a place somewhere in this. Either way I hope that Sasuke doesn't obtain the Rinnegan.
It may happen the way you described. I don't think it's a coincidence that Madara spoke of an eye that he was nurturing and then stabbed Sasuke through his heart shortly after. Madara may be aware that doing so would trigger something in Sasuke. I doubt that he's thinking of using one of Sasuke's eye as a Rinnegan (if that's even possible) seeing that he still intends on taking back his other Rinnegan from Obito. I also took his previous comment about using eyes as a stop-gap as being a joke.Actually, these equations make a lot of sense.
Also, now that you mention it, Senjutsu seems to be something that could effectively play a role in the awakening of this ancient doujutsu. Hashirama was going to give Sasuke something... if that something is chakra, maybe it is is Senjutsu chakra just like when Madara absorbed Hashirama's chakra.
It may happen the way you described. I don't think it's a coincidence that Madara spoke of an eye that he was nurturing and then stabbed Sasuke through his heart shortly after. Madara may be aware that doing so would trigger something in Sasuke. I doubt that he's thinking of using one of Sasuke's eye as a Rinnegan (if that's even possible) seeing that he still intends on taking back his other Rinnegan from Obito. I also took his previous comment about using eyes as a stop-gap as being a joke.