People have a wide range of ways they're handling covid at this point. For some, a dance will be a large portion of their weekly covid exposure, even with everyone wearing high-filtration masks. After a notification they may want to avoid visiting vulnerable relatives, get tested, or increase masking. But other dancers are regularly eating inside restaurants, participating in large meetings, having crowded indoor singing parties, where learning that one of a hundred people they shared a room with may have been infectious isn't something they're going to change behavior over.

I do think dances should continue posting publicly about positive tests and making it easy to sign up to be notified, but I don't think they should be requiring people to provide their contact information. I'm glad BIDA's made this switch, which I've been pushing for months, and I'd encourage other dances to rethink this requirement as well.