That's just how the CCP operates. Their ways are indeed very mysterious but they also seem to know what's up and plan surprisingly well.
I don't think China gets anything from withdrawing even though it is technically going to be China giving up "gains". I say that because from China's pov they're just retaking what they considered their's to begin with while leaving India still a fairly decent chunk of that disputed strip this whole time. China's claim run up to finger 2 iirc.
Jai Hinds will chalk it up to Rafales or Biden or US or undisclosed jawan heroism and effectiveness that mysteriously was not used for a whole year despite numerous attempts and changes in approach to repel PLA. That is somewhat of a loss for China but then again, if both are moving to pre-2019 positiions or so and India stops inflaming the disputed territory as much as they did between Doklam crisis and 2019, then that's relatively better for China not considering the gains.
I wonder how they'll enforce the withdraw this time. We all know how it went down last time in June.