Xi Jinping has communicated that lying flat is not part of his vision.
But, it can't be CCP propaganda. See, the key thing about the CCP (particularly Xi) is that the solution to a problem is always more control. The State is always telling you how to live your life--note that Chinese media uses a lot of terms like "should" and "correct", even when talking to foreign countries. Lying flat takes back personal control from the State, by refusing to participate in society, so it actually opposes the CCP's core value.
But, it can't be CCP propaganda. See, the key thing about the CCP (particularly Xi) is that the solution to a problem is always more control. The State is always telling you how to live your life--note that Chinese media uses a lot of terms like "should" and "correct", even when talking to foreign countries. Lying flat takes back personal control from the State, by refusing to participate in society, so it actually opposes the CCP's core value.