Sorry, no, that land didn't belong to Muscowy for 1000 years. before the 13th century, this land of Ukraine and Belarus was the heartland of the Kievan Rus -- these were NOT "Russian in the sense Moscow wants you to believe"
These people were the precursors of the Ukrainians, Belarussians and Moscowites, but due to subsequent history, these new people are NOT their cultural or political heirs. The Kievan Rus, specifically the city of Vladimir-Suzdal created a small hunting outpost called Moscow in Finnish-Ugric lands. This was not "historically Russian" either, but wild Taiga
History changed this -- with the Mongols coming, then the Lithuanians taking Belarus and then joining with the Poles
The Moscowites, on the other hand took their political philosophy from the Mongols
And the "land" -- from Mongol times until the 1700s this was part of various Turkic bands or Cossack hordes or belonged to the Polish-Lithuanian commonwealth.
The Moscowites only took this from the 1700s onwards.
so, this "belonged to Russia" only for the past 200 to 250 years, not more.
I remember your little history lesson from his early podcasts.