I put this on reddit also, but figure it may or may not be helpful to some here... I had VIN 2448xx (supposedly they started around 245xxx) or something like that, and yes I ordered it when no one knew new MCUs were coming out so I realize that I had no expectation of getting the new unit... However, I'm a huge researcher / nerd and I was sitting there reading all these threads about the new MCU and overly excited to get my new high tech car, I was also very hopeful that I got "lucky" and got one of the ones that had the new MCU. Well, after reading that others who ordered before me and took delivery before I was supposed to had new MCUs, I was pretty disappointed when mine came in to the SC for delivery prep this past Monday and my DS called me and showed me video and it was the old MCU. I asked them what I could do because to me that is a pretty big and material upgrade and to feel like I was just unlucky to get 244999 / 245,000+ before they did the upgrades felt like a gut punch. I'm young, highly tech savvy, it's an important and material upgrade to me. I've also never spent over $100k on a car, so that's another really important factor IMO.
Luckily enough my DS and OA were super awesome and they helped me transfer my deposit to a new order, so I'll definitely get the new MCU. Now I just have to wait until June to pick it up instead of this week, which is a bit of a bummer but I'm counting my blessings that they didn't make me forfeit the deposit in order to do that, which would have bitten but I probably still would have done it even if I had to. (The MCU upgrade seems pretty substantial to me from the videos I've seen, and the car's only going to get older from here right?) Also, my DS told me that the upgrade is not going to be retrofittable since it is integrated into the behind-the-wheel dash screen and etc. so it changes things so much it's not just a plug-and-play to replace type of upgrade.
I love Tesla and what they're doing. If it were just the vanity mirrors or something small, I wouldn't have cared and just been happy I was getting the car. The guys at Tesla totally understood my point of view being young and caring about the highest tech. available right now though, and so close to that cutoff. So I'm glad they were able to help me out.