

The announcement blog post linked on the bottom of the linked Turnstile page has some info on that
For Turnstile, the actual act of checking a box isn’t important, it’s the background data we’re analyzing while the box is checked that matters. We find and stop bots by running a series of in-browser tests, checking browser characteristics, native browser APIs, and asking the browser to pass lightweight tests (ex: proof-of-work tests, proof-of-space tests) to prove that it’s an actual browser. The current deployment of Turnstile checks billions of visitors every day, and we are able to identify browser abnormalities that bots exhibit while attempting to pass those tests.
uBlock Origin still functions the same. I doubt it’ll die in the foreseeable future because there’s interest in it, and moreso than in NoScript (my assumption anyway).
The uBlock Origin introduced https://github.com/uBlockOrigin/uBOL-home to cover the manifest v3. It’s a separate software. The original uBlock Origin remains functional like before.
Regarding the earlier point, this lite FAQ entry sounds to me like the main author is more committed to origin than lite.