There has to be another twist to this.. Madara planned this whole thing for over 100 years+ and for it to get foiled like that is BS.. I know he is focused on Hashi but I do believe Obito will use RT on him.
Obito is definitely playing on his own game here....as I already suggested....Madara most likely has his own agenda.
Considering his Uchiha stance with power as well as his past....it most likely both relates to Obito and Sasuke; however, it is his own version of changing the shinobi system.
Obito: Wishes to change the shinobi system through an infinite loop. Requires power
Sasuke: Wishes to change the shinobi system by destroying the tailed beasts/juubi. Requires power
Madara: Wishes to change the shinobi system with the simple act of destroying the shinobi world itself. Requires power