I don't know anything definitive but for what it's worth I went from gold (status match from 2010 UA 1P) to plat (based on 2011 eqms) about a month ago and had several reservations to fly within the 10 days after my status changed. For all of them, BPs printed with Plat. One was an M fare that cleared at the gate. After checking in online about 8 hours before flight time, I looked at the pda site and saw I was #1 on the list, so I'm pretty sure it was treating me as a Plat.