I'm fairly certain this this has nothing to do with the physical health of the battery, I think something changed (maybe the charge state algorithm?) in one of the recent updates. I've got 23k miles on my car and it had indicated range of 309 miles at 100% [279 at 90%} until one of the recent updates when it dropped to 272 @ 90%. Maybe it's more accurate, maybe it's a bug that will be fixed later, either way, I think our batteries are the same (physical health wise) that they were a couple months ago.
I agree. With so many reports lining up with recent updates, I think they've changed something.
I was previously charging to 80% (used about 20% capacity daily, on average) and seeing a large decline. Decided to try 90% for a few days with no effect (or worse). Last couple of days I decided to try 70%, and incidentally I seem to have gained a few miles back so far. I'm starting to wonder if rarely taking the pack below 50% was a problem for the BMS.