What they expected was it to collapse into a massive civil war that would have drawn everyone into it, if WW3 didn't kick off. The fact they went with a whimper was a shock to everyone. Left or Right.
In all fairness no body expected the Soviets to collapse. Fifty years of them being the big bad, everyone thought they were a superpower here to stay. The fact that they were a paper tiger wasn't obvious until after the fact.
You know I hate to say it but Nixon was right. I ended up in a wiki walk and found this old interview he gave shortly after the end of the Soviet Union and said a lot that is very right today.