So I'm guessing this number has been published by the Chinese authorities without anyone stopping to think about the possible implications of a 150,000 reduction in people age 80+ claiming this benefit. Unless there is some other plausible reason for such a dramatic change, the reduction would seem to be a rough proxy for excess deaths among that part of the population. One could project that number across the wider population using the relative proportions for the number of Covid deaths in different age groups etc (from countries with more reliable statistics) to get a number that is certainly not accurate, but would give a very rough idea, and with a huge margin for error, for the actual number of Covid deaths suffered by China. I think that would be a lot more realistic than the official deaths number which is about as reliable as a totalitarian regime getting a 99.9% majority in a referendum.
So what can we conclude from this ? Firstly any comparisons between how well China has done in dealing with Covid and any other country are literally meaningless; and any numbers specifically about Covid published by the Chinese authorities tell us what they would like people to think those numbers are, no more and no less.
As with the famines created by the "Great Leap Forward" we will never have a really accurate answer, but it will take many years before people can even produce realistic estimates.
Also, we can be sure the real number is bad enough that the Chinese authorities very much do not want people to have any idea at all of what it is.
Does this matter ? I think it does, not just because deception on a grand scale is a bad thing, but also because China has been touting its authoritarian approach to dealing with Covid as more successful than the approach used by the West, for example. We can now say we should not accept the numbers on which those claims are made as being reliable.