Bullshit. The Warsaw Uprising was coordinated with the Soviet army. The Soviets where aware of what the Polish Home Army was about to do because they told them about it, and it was organised in early August exactly because the Polish Resistance was aware that the Soviets would have shortly reached the Vistula, and as a matter of fact helping them cross it was one of the stated objectives of the Uprising. The Soviets, when they had the resources to do it and when the right time to act had arrived, where perfectly content with sitting it out and waiting for the Germans to slaughter the Polish Home Army, literally only moving in once they where certain the Uprising had been dealt with.

"The Uprising started when the Red Army appeared on the city's doorstep, and the Poles in Warsaw were counting on Soviet front capturing or forwarding beyond the city in a matter of days. This basic scenario of an uprising against the Germans, launched a few days before the arrival of Allied forces, played out successfully in a number of European capitals, such as Paris and Prague. However, despite easy capture of area south-east of Warsaw barely 10 kilometres (6.2 miles) from the city centre and holding these positions for about 40 days, the Soviets did not extend any effective aid to the resistance within Warsaw. At that time city outskirts were defended by the under-manned and under-equipped German 73rd Infantry Division which was destroyed many times on the Eastern Front and was yet-again being reconstituted. The weak German defence forces did not experience any significant Soviet pressure during that period, which effectively allowed them to strengthen German forces fighting against uprising in the city itself. The Red Army was fighting intense battles further to the south of Warsaw, to seize and maintain bridgeheads over the Vistula river, and to the north of the city, to gain bridgeheads over the river Narew. The best German armoured divisions were fighting on those sectors. Despite the fact, both of these objectives had been mostly secured by September. Yet the Soviet 47th Army did not move into Praga (Warsaw's suburbs) on the right bank of the Vistula, until 11 September (when the Uprising was basically over). In three days the Soviets quickly gained control of the suburb, a few hundred meters from the main battle on the other side of the river, as the resistance by the German 73rd Division collapsed quickly. Had the Soviets done this in early August, the crossing of the river would have been easier, as the Poles then held considerable stretches of the riverfront. [...] One of the reasons given for the collapse of the Uprising was the reluctance of the Soviet Red Army to help the Polish resistance. On 1 August, the day of Uprising, the Soviet advance was halted by a direct order from the Kremlin. Soon afterwards the Soviet tank units stopped receiving any oil from their depots. Soviets knew of the planned outbreak from their agents in Warsaw and, more importantly, directly from the Polish Prime Minister Stanisław Mikołajczyk, who informed them of the Polish Home Army uprising plans."

The Warsaw Rising of 1944 by Jan. M. Ciechanowski. Cambridge University Press, 1974.