I also have a December 2016 Model S and I know the plight all too well.
I get we’ve all got a choice to make here and have to decide for ourselves what we want from the car and what we’re willing to do to make that happen.
For what it’s worth, I upgraded to MCU2 two years ago at the high water price of $2500 and even knowing what I do now I’d do it again without a moment of hesitation. Not because of Netflix or any of the games garbage that I never use, but because the general interactivity, responsiveness, and overall UX is better in every way, and I spend a lot of time in my car.
For me, I decided it’s not worth depriving myself in the name of some notion of principle to make Tesla “pay up” and give me what they promised on hardware that was never up to the task. Tesla doesn’t care, and they’re not going to. They’ll do the “right thing” when they have literally no other choice, and I think you’re massively overestimating any “significantly larger” liability they might experience down the road. They’ve no doubt done the math and decided this is the most financially prudent course of action.
Is it worth lawyering up to make a faceless, remorseless corporation pay up after years of BS? Not to me but YMMV and I don’t judge or fault you for that decision. But if you’ve been waiting for FSD for six years and really want it, another $2k is really a drop in the bucket. We aren’t getting any younger and “6 months definitely” has come and gone 10 times over at this point.