Having two HV battery failures in 100,000 miles is terribly unfortunate. And it certainly begs several questions.
Thing is, though... you (the OP) have done absolutely none of the things that might help your "case."
Having a major pack failure at 21K miles would make most of us very suspicious of future HV battery issues. Especially given that replacement batteries in that scenario are nearly always refurbished, not new. Most of us would be watching that replacement battery like a hawk, and at the first sign of trouble would be at a Tesla Service Center. And yet you apparently drove nearly another 80K miles either blissfully unaware; or else ignoring things.
Most of us would document our concerns with screenshots and similar provable evidence. Most of us would collect and save any reports provided by Tesla.
Having taken our vehicle in for service, and being told that everything was normal, most of us would escalate/pursue those concerns then, or shortly thereafter, not months later, if we did not agree with that conclusion. And yet you drove happily towards your warranty expiration and didn't object until you had crossed that threshold.
Most of us, if we believed our odometer was optimistic and so we were being shortchanged on our warranty, would verify our vehicle - such being dead easy given the ubiquity of GPS devices and measured mileage markers on major highways.
And, finally, although most don't nerd out on their pack's internal particulars, leaving such minutiae to Tesla, some of us do pay attention to those stats. The detailed health of one's pack is available to those willing to pursue it.
Sorry again for your battery woes. But you've presented absolutely nothing in the forum here that would suggest you have any kind of "case" at all.