I think you'll be fine... it seems that, for M.Arch applicants at least, "decision made" meant "accepted", based on browsing the old threads on this forum. I applied to the same program and am still "under review", so the odds don't look that good for me.
(And not to over-analyze the wording of that e-mail... but it's notable how the message says you'll be receiving your "information package" shortly. An information package for accepted students, perhaps? If it was a rejection letter, it wouldn't be called an "information package", would it?)
P.S. I sent them an e-mail a while ago and the response that I got was the same as yours.