> I'm not sure this "test and release" strategy works unless absolutely everybody gets tested simultaneously.
They don't all have to get tested literally simultaneously; but the "release" part of the strategy can't start until the "test" part has covered everybody, or at least close enough to "everybody" that the difference doesn't matter. Note that that's how the strategy is stated in what you quote: if we can identify everyone who is contagious, then we can release everyone else. The "if" has to be complete before the "then" starts; that's what "if"-"then" means.
But contagious status is not fixed. If you test someone, they're negative, but despite sheltering in place they pick up the virus while at a necessary doctor's appointment, then their status changes. Granted, frequent follow-up tests might identify that change, but daily tests of a sufficiently large portion of the population have a number of challenges beyond just access to the tests.
The difference here is that you test everyone entering a certain location, not everyone in general. This is much easier, and allows testing to be focused on most needed areas. In effect, if you only go to the groceries once a week, you will be tested once a week. If you go back to office, you will be tested every day. The more you interact with people the more you get tested to keep the interactions safe
They don't all have to get tested literally simultaneously; but the "release" part of the strategy can't start until the "test" part has covered everybody, or at least close enough to "everybody" that the difference doesn't matter. Note that that's how the strategy is stated in what you quote: if we can identify everyone who is contagious, then we can release everyone else. The "if" has to be complete before the "then" starts; that's what "if"-"then" means.