I do use Twitter for school work, just not comfortably I prefer to post to the class blog & syndicate to twitter. The latest twitter crisis reinforces this.
I’ve never really liked the idea of Twitter or any other service being the official or main channel of schools (or government services). Schools should not be promoting an advertising service. My ideal would some sort of #IndieWeb set up, with micro.blog style aggregation & syndication. Federation might be a close second.