Exactly.
And what I have been saying for 15 years as the PRC has modernized.
We see the new DDGs, new FFGs, and the CV program...the J-20, J--11D, etc, Though portions of all are shrouded in secrecy, these are systems the US knows exists and is in fact spending money to counter them.
The DF-21D, IMHO, represents the last statement you made. It is all white papers and missiles on trailers that get positioned, but IMHO do not represent in the least a fully operational system. Yet, the US is spending beaucoup dollars to counter something, which I believe is a Sun Tsu gambit, exactly like what you are talking about.
Then there are programs the US may have simply heard rumors of, but does not know whether they exist or not or to what level of research, development, or actual building they are. As you say, in those instances it is hard to spend or develop something you know little to nothing about.
Anyhow...good analysis plawolf.