I think people should just stop trying to interpret data from a few days short period of time and then generalize. This is pretty much true on ALL fronts of COVID-19, data are instantaneous, they aren’t vetted and follow-up are inadequate thus those trying to make quick conclusions have been consistently wrong.
In this particular case large portion of new confirmed cases are asymptomatic at the time of testing doesn’t mean they’ll stay asymptomatic. Look at Diamond Princess, many asymptomatic at the time of tested positive became symptomatic over time due to long incubation period. You need follow-up data from these subjects after testing few countries provide.