$ rpm -q coreutils
coreutils-9.1-12.fc38.x86_64
$ uname -i
unknown

debugging the code in GDB the problem seems to be a configuration problem at build time. The problem is this little block of code:

            if (toprint & PRINT_HARDWARE_PLATFORM)
              {
                char const *element = unknown;
          #if HAVE_SYSINFO && defined SI_PLATFORM
                {
                  static char hardware_platform[257];
                  if (0 <= sysinfo (SI_PLATFORM,
                                    hardware_platform, sizeof hardware_platform))
                    element = hardware_platform;
                }
          #endif
          #ifdef UNAME_HARDWARE_PLATFORM
                if (element == unknown)
                  {
                    static char hardware_platform[257];
                    size_t s = sizeof hardware_platform;
                    static int mib[] = { CTL_HW, UNAME_HARDWARE_PLATFORM };
                    if (sysctl (mib, 2, hardware_platform, &s, 0, 0) >= 0)
                      element = hardware_platform;
                  }
          #endif
                if (! (toprint == UINT_MAX && element == unknown))
          =>      print_element (element);
              }
         

What is happening is both: 
 #if HAVE_SYSINFO && defined SI_PLATFORM
and 
  #ifdef UNAME_HARDWARE_PLATFORM
are false and so neither sysinfo nor sysctl are being called.

Reproducible: Always

Actual Results:  
unknown

Expected Results:  
x86_64 (or whatever the arch is)

also seems to affect: coreutils-9.3-1.fc39