I’m not sure who you spoke to when you arrived at this conclusion; there are tens of thousands of educators, projects who extensively use hashtags as a means to draw participation around projects, classes, community efforts, connecting beyond the classroom.
Many, many, many of them use twitter hashtag widgets on their blogs to show recent activity around a hashtag. Over the years, I must have created more than 30 for different classes and projects.
Let me be clear- collections/moments have uses but require manual curation and are by no means a substitute for the way educators use hashtags. Almost none of them are going to be able to figure out the API approach.
This is devastating and almost none of them are aware of this change (it seems to have been communicated via developer channels), and those that have heard have no idea what this means.
I can guess that for Wordpress, some developers will create new widgets that work with the API.
But this has been twitter’s decision, so none of us have any say. Just know that it is not an insignificant change and it has not been communicated to the people it will affect.