Those are good thoughts. In the long term, 6C/24C is going to be turned into a taxiway; based on that, I don't think they were planning on having simultaneous ops for 6L/24R & 6C/24C. However, it is possible in the short term -- since they're going to be extending 6R/24L, they'll probably have to close it for at least some period of time, during which they'll probably use 6C/24C and 6L/24R.
During busy periods in the past (before 6L/24R), they have used 6C, 6R, and 10 simultaneously (6R was LAHSO 10).