[QuarterReptile]

I don't have any insight into their motives, but that's not the trial they performed. The only time blanket testing occurred was to make sure no one in the vaccinated group was going to get counted as a breakthrough case when they got covid before full vaccination. Otherwise they only tested participants when they presented with symptoms, thus "these data do not address whether vaccination prevents asymptomatic infection" [0]. Accordingly, it was not testing Covid-19 infection except to the extent that it presented significant symptoms. The trial also didn't address (not clear how it could have) your ability to keep passing the virus along once vaccinated.

[0] https://www.nejm.org/doi/full/10.1056/nejmoa2034577 (see p 2612 of attached pdf).