Also, if you are updating "right away" it is presumably because of some specific vulnerability (or set of them). But if you're in an "update right now" mode you have the most eyes on the source code in question at that point in time, and it's probably a relatively small patch for the targeted problem. Such a patch is the absolute worst time for an attacker to try to sneak anything in to a release, the exact and complete opposite of the conditions they are looking for.

Nobody is proposing a system that utterly and completely locks you out of all updates if they haven't aged enough. There is always going to be an override switch.