The movie clip depicting the MBT that has been taken over shows a T-72B3 - the oldest of the Russian MBTs but modernized to a relatively modern standard. Many of the Russian T-72Bs received that upgrade. According to the record of visually confirmed losses listed online by the Orixspioenkop body, Russia has lost at least 36 T-72B3 MBTs.
Notably, in the case of the MBT captured by the Ukrainians in Sumy, the Russians have lost an example prepared for the Red Square Victory Day Parade, with a single-digit number on the turret, and St. George's ribbon in the paint scheme, symbolizing the 1945 Victory and the Moscow's intention to regain its superpower status, with influence similar to one dating back to the times of the Empire. Interestingly, the ribbon has been adopted as a Victory symbol solely in Russia. Other former USSR republics cut off their ties with that symbol, establishing relevant symbols of their own.
During the last pre-covid parade in Moscow, one could witness four T-14 Armata prototypes, six Terminator tank destroyers, and 10 of the aforesaid T-72B3s. The fact that an MBT as such is taking part in combat may mean that Russia is depleting its fighting vehicles stockpile.