Conclusions are never conclusions; they are only ever opinions which are constantly being revised. When Mao Tse-Tung was asked what he thought the historical impact of the French Revolution had been, he said that it was too early to tell.
I think that the collapse of the USSR (and its satellite states in Eastern Europe) was a long time coming, and was only incidentally influenced or hastened by Thatcher and Reagan. The USSR's birth rate had been declining, death rate increasing, and health and industry were collapsing gradually for 10 or 20 years. The imminent collapse of the USSR was actually predicted by a number of American economists and sociologists in the 1970s.
I think that (among other things) the balance of power between the USA and USSR helped to keep a lid on dormant nationalist and religious tensions in e.g. Afghanistan, and the world is worse off without the USSR.