I don't see how Tesla wins either way. If it's not a safety issue and they go with "prolonging the battery", then the implication is that the batteries aren't lasting as long as they should have, so they have to remove features in order to stretch out battery life. So they lose the battle either way. If they identified a safety issue that required a change in order to prevent fires, that safety issue should have been reported to NHTSA before they issued a fix, else there is no tracking of the issue and fix. NHTSA is pretty specific on that front: safety issues have to be reported within 5 days of discovery. There is no disclaimer for "unless you already fixed it". On the other hand, if it's nothing but "prolonging the battery", many will perceive that as an admission that their batteries were discovered to not last as long as they should. So it's not a good situation either way.
Mike
Rather than "not last as long as they should", I think it more likely it was discovered that they were not going to last as long as the rosy reporting of the BMS was indicating over the last few years.
This seems to be in line with reports here of capped cars showing CAC results that keep getting "more better" than the average, which could be because the average gets lowered as they systematically, selectively, incrementally "correct" the range degradation numbers the BMS had been showing everyone.
The big problem is we are still in uncharted territory on how long we can expect our batteries to last, what is a normal rate of range loss, and what options we will have for replacement/refurbishment at what cost after warranty expiration.
Is a Tesla economically an 8 year life car, 10, 12, 15, 20...?
I think that's a really big deal, much more so than the fastest time around the Nurburgring in my book.