He’s probably been taking a closer look since the level of corruption in Putin’s armed forces was exposed. Not saying he didn’t think there was any in the PLA, but maybe what’s been going on in Russia since they invaded Ukraine has been an eye opener for him.
China accepted the corruption when their economy was going very, very, well.
Now, not so much.
China always accepts corruption, it’s just only if you’re in the ruling faction.
Authoritarians love using corruption to crack down on political opponents.
They’re not accepting it from the Generals who they just purged.
This is basically rule number one in the autocrat’s handbook: Rule something as illegal but make it necessary (e.g. give your public servants a near-zero salary, making them dependent on taking bribes to live). Then at any point the leaders have the legal grounds to arrest whoever they want for ‘corruption’. It’s a very common tactic.