h, yes, the economics of forced obsolescence strikes again.
Um... iPhone SE and 6s aren't going to stop working the day Apple stops updating iOS for it.
Never said it would.... Apple is simply stopping security support which makes use of the device ever so slightly more risky.
Not being able to update to iOS 15 doesn't mean that security support stops.
Apple often continues updating the OS of older HW even when it is not the latest version.