Why are they saving more? Is it precautionary saving, greater availability of various domestic financial instruments, aging, transfer of money abroad (which compresses consumption at home), or possibly something else like overstated income in which case reduced consumption may be simply a reflection of lower income of the urban elite?

The answer is probably "all of the above and more", but we know that China has increased capital controls in an attempt to fight capital flight. Perhaps the increased savings rate is a systemic response as those looking to move their money out search for replacement effective ways to do so.

Alternatively, perhaps the lowered spending metric is the evidence of success of capital flight as the author posits. As in, the increased spending is occurring but not under the domestic measurement as the spending is happening outside the country.

It will be interesting to see the data in the months and years ahead to get more clues.