But I think that you might miss the main point here for the consequences they would have to face:
1. Before declaring symptoms you can be already ill and contaminate others
2. You can never declare symptoms and never be ill, still, you could contaminate others as a healthy bringer
So, according to me, the main point is that if they don't test everyone like in South Korea, Germany, Taiwan and so forth, they expose the population to contract the virus anywhere, anytime as soon as they stop the lockdown. It's not a matter of one being ill, it's a matter of one making others ill without any control about it.
Then, it would make the current lockdown useless. This is why, it's a stupid thing to say and do but on another hand, maybe a clue to help understanding things here.
It's always the same question that we ask ourselves regarding the events for years... and the current global situation adds one more step to the process, and still, some of us don't even doubt a bit about our reality and PTB go on with their agenda without blinking an eye it seems.
I understand you, and this question was already being asked to our health minister, and he explained that not doing the testing for everyone doesn't change anything in their policy. Because this testing is dependent on time. Today you can be negative, and tomorrow you can be positive. So even if they do test everybody, they cannot test everybody at the same time. So the virus can still theoretically spread in the population even if everybody is negative on testing! It might sound silly, but it's true if you think about it. So they don't have to face any consequences. The plan is simply brilliant, as long as people believe in it.
So mass testing is pretty much useless for people who do not have symptoms. It's only good to show the people that the pandemic is rising and create a panic. Or to delay the lockdown, because as long as there is a single positive person they don't have to declare an end of pandemic. And that is what they want to do now, to buy the time until they make the vaccine. In China they said 14 days after the last positive person, but this night our infectologist said that we will go for double of that, i.e. 28 days after the last positive person to declare the end of epidemic.
But even if your country gets to zero, what about other countries which are behind, or on the other half of Earth where there is a season of viruses going around during their winter? You cannot stop the lockdown if there is a single country in the world that can import new cases into your country. Oh no, the mass vaccination of entire planet is our only solution.