“Company officials said they will try to reschedule ‘Poetry in Motion’ for a later date, but for now they just hope to begin the season with the planned premiere of Sir Kenneth MacMillan’s story ballet Mayerling on Sept. 21. As with so many other things across the devastated city this week, that will have to be a wait-and-see matter. The plan depends on the availability of the storm-damaged Wortham [Theater Center], whose basement floors and main stage flooded.”