My first thought is they are using old stuff in the lead, knowing it’s going to get wrecked. It still points to a shortage of tanks, and also they are sacrificing those crews, so you know they aren’t well-trained, and they’ll get fucked up anyways at some point.
But we also know they were producing about 20 “modern” tanks a month, and were supposedly bumping that up to 40 or more, but it was still not enough to keep pace with tanks being destroyed in Ukraine (their “massive” reserves were originally keeping the front supplied with tanks). And they were also restarting production lines for turbine engines for tanks, but they were basically hand-producing them, so not in any great numbers. We might have reached that point where their reserves of T-6x/T-72s are depleted, or at least their ability to deploy them everywhere (parts/engine shortages).
If this starts happening more and more, that’s going to get real interesting.