The counterpoint to this is that you can't just wait forever before making a decision. At some point, you'll have to do with imprecise data, and for a pandemic that is developing very rapidly, you can't just sit back and do nothing (well you can, but then you have to make an argument for why this is a good option).
As to the point of whether utilitarianism is a good ethical framework... well, at least no non-consequentialist ethical framework has ever convinced me. A naïve reading of utilitarianism has its problems, of course, but those can be accounted for; but the classical Kantian conundrum of not being allowed to lie to a murderer seems silly to me. Plus saying "principles matter" has just as many problems as the utilitarian approach, as nobody will be able to agree on those principles.
As to the point of whether utilitarianism is a good ethical framework... well, at least no non-consequentialist ethical framework has ever convinced me. A naïve reading of utilitarianism has its problems, of course, but those can be accounted for; but the classical Kantian conundrum of not being allowed to lie to a murderer seems silly to me. Plus saying "principles matter" has just as many problems as the utilitarian approach, as nobody will be able to agree on those principles.