Wow, congrats to you. This will be my 4th year in the gray lot and was told that I most likely wouldn't get a b3 upgrade. Guess things haven't changed as much as we thought up there.
Edit - Spoke with Chris at the ticket office, very nice guy, who said they were working on the parking and based on availability I should be able to get in to the B3 lot. He took the time to look at my account, figure things out and said that hopefully I would find out within the next couple weeks but maybe not. Guess it is still a game of who you talk to, didn't ask about seat upgrades though as Inwas already fortunate with my previous upgrades.
He didnt have an answer to why some people already got the offer and got it "out of turn," but I didn't expect him to as those things are bound to happen when dealing with 90k seats and who know how many parking passes.