ISA's are to hardware what API's are to software. They simply provide a spec to conform to. ISA's say little to nothing about the hardware implementation itself. That's the real value and something that every firm that has CPU IP guards.

And sadly China isn't lacking in stolen valuable CPU IP. The Chinese branch of ARM went rogue last year. I think its a safe assumption that any sensitive information they may have had is no in the hands of the CCP and will be used to its full potential.