The new tower was built with parallel 16/34 runways in mind. There is ample room to install extra workstations to accommodate an extra ADC and SMC. In fact it was considered prior to the 09/27 decision. The real problem is only having one terminal building on the eastern side. Traffic taxiing to/from
16R / 34L would need to cross the eastern parallel runway or its undershoot area. Parallel 09/27 is much easier.
16/34 would probably involve flattening the hill north west of the runway intersection. This would have a huge environmental impact.