I can't confirm whether your approach is legit (though vPro does seem to be relevant), but I find my work machine (2015 15" rMBP) has it, and my personal (2013 13" rMBP) doesn't.
Specifically, the string you want to `grep` for is "machdep\.cpu\.brand_string".
Specifically, the string you want to `grep` for is "machdep\.cpu\.brand_string".