I don't understand. Why didn't Chandrayaan crashed a long time ago ? 200 km high is peanuts.
At the end of an extended mission, Ebb and Flow were sent purposely into the lunar surface because their low orbit and low fuel levels preclude further scientific operations. They impacted at mountain near Goldschmidt crater on the lunar near side.
I was also surprised by this. It was said at the time (2009) to be likely to crash in 3 years. They did not go into a frozen orbit deliberately, so it must have been by chance that the orbit were quite stable.
there is the remote possibility that Chandrayaan-1 despite loss of all communication could have maintained functionality including its ACS for a bit thus delaying the start of its decay rate.