yes, USSR squashing Kwantung army may have naturally led to a scenario where USSR forces could flood down south into China, Korea, may be even invade the North Japan, etc. with US having no troops there to "meet" USSR forces like it happened in Europe. Whether USSR had such plans doesn't matter really.

It is very telling that USSR offensive on August 9 was according to the plans made together with US months in advance, and so US could hardly time the 2 bombs better - one on August 6 and another several hours after the start of the offensive - to make such an extremely clear message.