I have a related problem; I'm not sure if your solution here applies.
I've just started using Word in Office365. I do a lot of editing using Track Changes. I'm finding that comments I make are identified by my Microsoft Office 365 email address -- not my name. In older versions of Word, this could be adjusted in Word Options, but I see no place to do that. I've gone in to File:Options:General and personalized by copy by putting in my name/initials, but that doesn't change how I'm identified when I comment on a document.
How can I edit this so that it reflects my name and not my email address?