default or selected kernelversion does not have config value CONFIG_HARDENED_USERCOPY_DEFAULT_ON.
Result is shown for kernelversion 6.6.86

Harden memory copies by default

configname: CONFIG_HARDENED_USERCOPY_DEFAULT_ON

Linux Kernel Configuration
└─>Security options
└─>Kernel hardening options
└─>Bounds checking
└─>Harden memory copies by default
In linux kernel since version 6.6.86 (release Date: 2025-04-07)  
This has the effect of setting "hardened_usercopy=on" on the kernel
command line. This can be disabled with "hardened_usercopy=off".