Did Tesla release the 2023 software with verbiage of all the limitations and caveats that would make it clear how outdated and dangerous it was then, or did it announce it as being awesome and safe? If it was the former, I'll eat my underpants. If it was the latter, how can we trust anything written about the adequacy of FSD today?

Old data? As in November 2023 --- roughly 17 months ago?

Has there been any really significant improvements to "Full Self Driving" since then.

Nope. Still classified as Level 2 ADAS (advanced driver assistance system) per the National Highway Traffic Safety Administration. FYI, under this internationally recognized rating system, "Full Self Driving" would be Level 5 --- not Level 2.

Lots of companies currently offer Level 2 automation --- Hyundai for example. Most of them are not bold enough to put passengers in a Level 2 vehicle without a driver.

Injury lawyers must be so happy over this they are about to pee their pants.