Silence equals acceptance which leads to reduced membership.
I feel your frustration—remember Vatican II? But if the Church took steps to refute all the junk theology out there, individually, it’d have time & resources for nothing else. If there were any doubt about what the Church teaches on the issues Nancy feels she must address, there’d be no fuss whatsoever about what she’s preaching. Because there’s a “fuss,” it must be pretty clear where the Church stands, thus obviating any need for clarification from the bishops. The way I see it (and it’s probably not exactly the most charitable reaction), she’s not worth an excommunication.