We're excited to announce that we've fully migrated the Xbox Forums to their new home, here on the Microsoft Community forums!
As of today, going to forums.xbox.com will redirect you here to the Xbox area of the Community forums. We've moved all of your existing threads over so you can continue and start conversations with the new forums experience.
We sincerely appreciate the feedback you have provided over this transition and can't wait for you to check out the new Xbox Forums!
On the Xbox 360, this was possible as long as account B was playing on the same console the game was bought on (or the license was attached to, if ever transferred) and connected to Xbox Live. There's no Support article regarding this on Xbox One, you can
test it out by trying to access the game from "My Games and Apps" on account B.