It is hard to describe the isolation of the members of those communities, even in one of the most technologically advanced countries in the world (Israel). For outsiders, avoiding the news is nearly an impossibility. We can't even enjoy a nice several minutes on a bike forum without reading something about Trump this or Trump that. The cloistering of the Chasid is comprehensive, and they are highly susceptible to rumor and inaccuracies as a result. See the measles epidemic from last year. I think NYC kind of forgot about how out of touch these people still are, didn't push the information through the Rabbis strongly enough, and didn't foresee how much of a problem their way of life was going to be once Covid19 entered the community.