No not really dont forget you still have things mounted in the same place.

The twist (or cornering force) is taken out by the dampers that now work independantly from each other. As long as they are not knackered 20 odd year old items it will be 100% fine.

An ARB will not stop a shell from twisting as it is basically acting just like a spring. The rear ARB is left untouched anyway but some race cars do disconnect it sometimes to change the way the car steers.