Well, it's possible the author believes what they wrote in which case it would be "false information believed to be true intended to teach" but I'm pretty sure this is active misinformation.

I'm not sure which particular thing public health people said that you're complaining about in the last part of the section- but I don't really think that public health leaders who communicate things which aren't 100% correct are dissemination disinformation. That's sort of a pedantic and uninteresting argument to have about the philosophical nature of information.