Trying to achieve herd immunity (and hope it lasts) is a political option.
But if you are going to do herd immunity, it is dishonest not to say so.
Grandma and grandpa want to know as they are the losers in that scenario. They may want to vote for a different governor who is prepared to wait for a vaccine, which is an alternative option (and I think a better one).
It's a question of honesty as much as anything. By the time you get to Yale, it's too late to learn integrity.