It appears Trulia pulled the sale information when your purchase was recorded this fall after the property expired. The information is as recorded in Oakland County public records. If you would like a copy I can email it to you. If you used an agent to purchase the home, they would also have access.
When your tax bill comes, you could consider trying to decrease your taxes based upon the lack of a bedroom, but expect a fight from Wixom and possibly a visit to your home during the process. Most likely property taxes will decrease for the entire area anyway.
Welcome to the "neighborhood".
Thank you for contacting us about this. This public record information that we show comes from data made available by the county assessor's office. Please contact your local assessor office to ensure that they have the most up-to-date information on file for your home. Once they update their information our display should update automatically with the new info.