I have a different perspective. In a drug trial you have to prove that a new drug is safe before handing it out to a bigger number of people. The default case (if you don't test the drug) is that nobody gets it.
In this case, it is different. People will put pressure on the government to allow concerts again rather sooner than later and the default case is probably that there will be concerts again before the Corona situation is over. If you don't do the test, you have to make the decision whether / when to allow concerts again blindly.
So basically you have the situation where people will take the new drug anyway and you have the choice whether you want to test its safeness before they do.
If you do the test and it turns out to be unsafe, at least you have good arguments when you need to make the decision.
In this case, it is different. People will put pressure on the government to allow concerts again rather sooner than later and the default case is probably that there will be concerts again before the Corona situation is over. If you don't do the test, you have to make the decision whether / when to allow concerts again blindly.
So basically you have the situation where people will take the new drug anyway and you have the choice whether you want to test its safeness before they do.
If you do the test and it turns out to be unsafe, at least you have good arguments when you need to make the decision.