I think they meant that they copied the keys from Windows to Linux so that they can easily pair their Bluetooth device without having to repair when booting into the other OS.
So without doing it, I think you have to forget and repair every time you want to connect your Bluetooth device if it was paired with the other OS. If keys are copied, you can just connect it without hassle. I did it so that I can pair my controller by just pressing its Power button, and it does not worry about whether my computer is running Linux or Windows.
I think they meant that they copied the keys from Windows to Linux so that they can easily pair their Bluetooth device without having to repair when booting into the other OS.
https://wiki.archlinux.org/title/Bluetooth#Dual_boot_pairing
So without doing it, I think you have to forget and repair every time you want to connect your Bluetooth device if it was paired with the other OS. If keys are copied, you can just connect it without hassle. I did it so that I can pair my controller by just pressing its Power button, and it does not worry about whether my computer is running Linux or Windows.