Poles would never let that happen under Russian domination. Kievan Rus’ are Russian speakers, while Poland etc are not. There is no will to recreate the USSR in Russia
Old East Slavic (traditionally also: Old Russian, Belarusian: старажытнаруская мова; Russian: древнерусский язык; Ukrainian: давньоруська мова) was a language used during the 10th–15th centuries by East Slavs in Kievan Rus' and its successor states, from which the Belarusian, Russian, Rusyn, and Ukrainian languages later evolved.
With time, it evolved into several more diversified forms, which were the predecessors of the modern Belarusian, Russian, Rusyn and Ukrainian languages. The regional languages were distinguishable starting in the 12th or 13th century. Thus different variations evolved of the Russian language in the regions of Novgorod, Moscow, South Russia and meanwhile the Ukrainian language was also formed. Each of these languages preserves much of the Old East Slavic grammar and vocabulary.
https://en.wikipedia.org/wiki/Old_East_Slavic