“As dancegoing New Yorkers might hope, the living choreographers for whom their city is most renowned — Merce Cunningham, Paul Taylor, Twyla Tharp, Mark Morris — are all scheduled to present new works in the coming 12 months and to revive beloved works from their past. So far so good. But too little of it will open in New York City. And there is no knowing when or even if some of it will be seen here.”