Seems possible, I joined MyGamerCard.net and the leaderboard there for the AVS forums the day before I got this email...
Makes me glad I took their advice and used a different password than my XboxLive account one.
Perhaps someone used my information off there.
Plus the wording of this email just immediately ticks you off after reading it (At least it did for me). I certainly wouldn't word something the way they did if I wanted to keep a customer.
I think I might just might make sure this is solved though by borrowing cc information from my parents for my information so theres a valid card tied to my account just in case (Doing this through the console itself to be safe, certainly not through the links in this email they sent) since I don't plan to be buying anything by charging on there anyways.
Thanks for the help everyone.