It's a wacky year. The B1G can make any rule adjustment they want on the fly. Other conferences are doing it. The ACC cancelled games to suit their needs. The PAC12, on the fly, allowed teams to schedule make up opponents when their scheduled opponent could not play.
Indiana would have a huge beef with the rule change. And who knows, maybe the ADs will take their side. But, because they lost head to head against OSU, the B1G ADs have a path to allow OSU to play in their place.
Aside from that, OSU could play in the 2nd place game and still accomplish the goal of making the playoffs. So the rule change may be unnecessary.