Тhe collapse of the USSR was a blow to Russia. The USSR represented Russia, even though there were many countries in it. And for the modern Polish elites, what is bad for Russia, is, in general, good.
One of the recurring Pro-Kremlin narratives Elites vs. People, describing Polish elites as Russophobic. Russophobia is often used in pro-Kremlin disinformation as well. Similar cases can be found here and here.
This statement appeared after the head of the European Council Donald Tusk posted on Twitter: “The collapse of the Soviet Union was NOT the greatest geopolitical catastrophe of the century. The USSR collapse was a blessing to Georgians, Poles, Ukrainians and the whole of Central and Eastern Europe. And also to Russians."