This happened to me a few years ago. After 4 years of ~100 nights a year, I decided to go back to school and hence stopped living on the road. I assumed I would get dropped to Gold the next year, but SPG surprised me by offering me Platinum for another year for my past loyalty. While I didn't get to take much advantage of my "unearned" status during my 2 years in school, it certainly helped cement my decision to remain loyal to Starwood now that I've returned to my weekly travel.