So a little more context because some have asked and maybe it helps...who knows. I'll also see if I can summarize it all again succinctly. (BTW, all of this info y'all provided is really really helpful.). This is a little long, but it'll detail the whole buying process with dates in case that's relevant.
I started shopping seriously for a Used Model S in September, 2019. At that point I only knew about the used car section on Tesla's website and I did all of my shopping there. I avoided 3rd party sites. Around that time I was also linked up with a Tesla sales rep, Jonathan. He told me about EV-CPO and texted me the link and told me about how I could go about narrowing options etc. I basically lived on the site for next two and a half months.
Since I was buying used, I knew there were at least two things that I HAD to have because I planned to keep the car for at least 5-7 years and I did NOT want it to be basically "phased out" of future updates: HW no less than 2.0; and either FSD or EAP. At that time I couldn't get a really clear answer on the difference between EAP and FSD, but it seemed to me that FSD was ONLY possible on cars with the new more advanced array of cameras and so that became the cutoff - the car had to be FSD. (I'm still not sure if this is actually the case, but that's what I thought at the time, so that's what I went with.). It was all about future proofing.
Also, at the time I didn't know squat about MCU differences, so that was not a factor. I sort of wish I had known, but that's on me for not learning. Anyways, aside from FSD (which ensured cameras, HW, and AP versions) I had some other options I really wanted and proceeded from there. Signed up with EV-CPO, set up my configurations, and started getting the regular updates and emails. I QUICKLY learned how fast these things sold because I missed basically ALL of the cars I wanted.
Then, December 17, 2019 I found one that almost exactly fit the bill (it was blue instead of silver or gray). I could live with blue so I paid my $100. The next day, the 18th, I emailed my sales rep Jonathan and arranged a call to ask him about the process going forward, the timeline, shipping, and to clarify the FSD Capability question. We got everything cleared up except Capability. He told me that it was something he would have to confirm because it wasn't like he just had that info on hand. We then lost contact while I waited for the car to ship. Delivery was delayed for some reason and then we texted again on December 23rd and at that point I was handed off to a different sales person, a female whose name I can't recall. I still didn't have an answer on FSD Capability.
I took delivery in Atlanta on December 28, 2019. Car parked out front, looked gorgeous, I was excited, and the (super nice) tech walked me and my wife through some of the details before leaving us to just play around with different features (which he said was the best way to come up with questions we might have). Before he left us alone though I definitely remember asking him specifically about Autopilot, how to engage, what it had, etc, and specifically whether this vehicle was indeed FSD. That had been a deal breaker for me from the beginning. I was in the vehicle as he went through the options and he absolutely looked at the features and exclaimed that oh yeah!, it does have FSD and told me all about summon and lane changing and how to work nav on autopilot (which I then used driving the 2 hours back home).
They also set me up at that time on the Tesla app. The tech said it could take some time for it to get set up, but within 30 minutes I was connected and everything seemed fine. It wasn't until maybe a week or two later that I even noticed that FSD was still showing as an available option in the app (for $4,000). I knew I already had FSD so I thought it was odd, but didn't think anything of it because, well, I had it. I used summon on occasion, I used Nav on Autopilot a lot, it all worked.
Then just this past week I learned about the free HW3.0 upgrade for FSD cars (from a March 2020 article from Inside EVs). I went into my app to schedule the upgrade first and then watched the video. It was only then that I learned about the potential differences between EAP and FSD and the possibility that my car may not have actually ever had FSD "activated". I checked my HW version in my car, checked again all the autopilot options (to see if anything was grayed out...they weren't) and then logged onto my Tesla support page on the tesla website. That was the first time that I ever noticed that Enhanced Autopilot was listed and NOT Full Self Driving.
I then got on here and started asking questions. I posted pictures of the "window sticker" in an earlier message showing that the only way it was ever advertised to me was "Full Self Driving Capability".
If there are others details, I'm happy to provide them. From what I can gather reading replies, this isn't necessarily something that Tesla intentionally misled me on - it sounds like perhaps all of the sales reps and the tech were equally as confused. What I'm concerned about now is that I actually AM going to have to pay $4,000 for something that I thought I've had all along and that was very specifically a deal breaker from the very beginning. I must have looked at 80 or so cars before buying this one, so it's not like I just got the first one that came up. I'll keep this updated as I try to get in touch with Tesla today.