Many weapons systems around today may have been designed in the 1980’s or even the 1970’s.
Do you think that an oddball memory chip or any other electronic component made 25 years ago will still be manufactured, stocked or supported by a US manufacturer today?
So buyers must go to the secondary market, where China is a big player in the scrap and refurbishment market. A lot of electronics dis-assembly and scrap collection is done in China (although it is moving to even cheaper places now).
Of course, China is also the king of fakes and counterfeits too.
So put that all together and YES - there probably are a lot of counterfeit or remanufactured parts in US weapons systems.
Actually, there’s a fix for that problem, and has been for years. One company makes programmable emulator chips that can be burnt-in, and now they’re functional dupes of old, out-of-production chips. And, of course, they keep a library of old chip designs, to produce on the fly.
They’ve been doing that since the early 90s, and it’s apparently a nicely profitable sideline. . .