Like I said, it worked for me all last season, and it appears that it would work at least initially this year. They may block it at some point (doubtful), but I just say I signed up for the service to block ad's which is it's purpose, and gamepass was offered with live games so I used them. It's not as if I used the service to gain GP, it was a byproduct of it. How to Geek which was linked to earlier in the thread, is a very reputable website which gave instructions for this very thing.
This is akin to people who use browser add-ons to make netflix think they're overseas and therefor gain access to UK version of netflix, and the tons extra content that goes along with it, or how about netflix, amazon prime, or HBOGo password sharing. It's publicly frowned upon, but what are companies alternatives, refuse the money? They've turned a blind eye to it time and time again.