Jeff Butts, the Mac Observer:
Beginning in iOS 16, Apple has added the ability to push out security fixes without requiring a full iOS update. This can be much faster to install, since the patches are generally much smaller. Wednesday, Apple released one of these updates, called a Rapid Security Response, to testers running iOS 16.2 beta 3. After some time, we learned this update was only for testing purposes.
When I saw this update on my iPhone earlier this week, I assumed it was fixing some kind of critical vulnerability. Alas, it seems it contains no material changes, even though it was over 70 MB for me. I wish this was better documented as a test, but it is good to know this capability exists and, as far as I can tell, appears to work as intended.