While not an official, I would lean towards the latter since if you call in "as a customer" that device will have only been on your account and/or will have not met the requirements and that is assuming that even then they would since you were not the customer who purchased the device from them in the first place.
Can't your friend just put the request in? He is or was obviously a TMO customer and would be eligible to request an unlock.
I've read and re-read the eligibility for locking document online, but I have a question about its limitations.
I have bought an iPhone 6S off a friend, fully paid off, but it is not accepting any non-T-Mobile sim cards, as it is assumedly still locked.
I know I have to be a customer of T-Mobile in order to request an unlock. So my question is this:
If I got the cheapest pre-paid SIM option and activated the phone under it, would I then be free to have it unlocked as a customer?
Or would the "ownership" period restart with me as the new owner, inasmuch as having to use it x months or spend x amount of credit before I am allowed to request an unlock?
If you got it from a friend have that friend request the unlock, and it should go through if everything is free and clear, and he's in good standing. If you can't go through that friend then everything starts over for you.