Loop,
My opinion is that the open slots for the 747 will go (initially at least) to 767 FOs that have completed their bidding freeze and have now been waiting for 747 slots to open up since about late September. We have NOT hired ANY 747 FOs since then...so, the current 767 FOs will take the first 20-30 747 slots that become available. After that number, the company has the option to release others from their bidding freeze but have not done so in the past, so we shall see.
But for now, it might be best to expect a 767 class if you are in the pool now.