It makes no sense to say that we should avoid lynches on day one unless we know for sure we have a mafia cornered. There is only one way to know for sure if we have found mafia, and that is to lynch throwing away potential information in the hope that you'll happen to pick the right night target puts town at a disadvantage.
I could see the reasoning behind a general day one no lynch vote if you don't want to pay attention to the game and we could just play forever and take our time with the lynches. But, in reality a lynch of any kind gives us a lot of information before heading into the night. It gives everyone in town their second fixed point of reference (another confirmed player) and gives reason to go back an reread the lynched player and how the case against them was built. Invaluable information and potentially something that could improve the accuracy of Night One.
And that is just in a normal setup, now we have just 5 Days to weed through 17 players, it makes getting solid information even more urgent.