The companies selling Linux systems including GPLv3 code plus hardware are happy to include Installation Information.
Installing Windows on a Mac is not relevant here, because Installation Information is "information required to install and execute modified versions of a covered work in that User Product from a modified version of its Corresponding Source." Windows is not a modified version of a covered work, and so the ability to install Windows doesn't imply the ability to install a modified version of a covered work.
I would be surprised if a Samsung smartwatch had any GPLv3 code. Android rewrote a bunch of userspace specifically to avoid GPL (any version).
System76, Asus, etc. don't run afoul of GPLv3 because they don't restrict what you can install.
Most Android devices also don't violate any GPLv3 licenses, because they don't include any GPLv3 software. GPLv2 software like the kernel doesn't have this same restriction.
Apple decided to take the approach of "don't include GPLv3 software" so that they wouldn't have to worry about it once they fully lock down their computers. If Apple included a modern Bash with MacOS, they would need to give all owners access to any compilers or signing keys necessary to modify Bash and replace the binary that Apple shipped. Today, it's possible to do that. Tomorrow, it might not be.
Note also that you can't install custom software on a Samsung smartwatch, but you can install Windows on a Mac.