This fits with the old Russian tradition that the people at the top are lied to and accept it as long as things are going reasonably well. When things go wrong, getting the truth permits an easier change in leadership and policies. Corruption can always be claimed and proven because the Russian system runs on corruption.
In addition to a purge of the military leadership, Putin is now publicly talking both nuclear escalation and ceasefire with Ukraine and the West, meaning that he blusters a choice between a nightmare and a deal. These are not the moves of a player with a winning hand.
As the new Minister of Defense Belousov has no doubt told Putin, Russia might win in Ukraine, but she cannot win or even continue the war at a bearable cost. That means that it is time for a purge and lining up people to blame. With that underway, Putin will have greater domestic political freedom to make concessions.
This is typical of Eastern European/Asian countries. The Generals that actually produce results are feared because of their competence. Sadly, that way of thinking is infiltrating into the US Military upper leadership. If I was still serving (thank God I’m not) I’d never trust a General and I’d be wary about a LT Colonel or Full Bird.