We have extended the ability for Airtable to update existing event data in Elevent--not just be a source of one-time imported info. Now you can continue to change, update, and manage your events and event data in Airtable without creating duplicate events in Elevent.
As long as the Event Names in Airtable match Elevent, data from Airtable will update the event data in Elevent. Note that this only applies to events, not showtimes on the schedule. Those are still only imported once.
This is an opportunity to rethink what is the most efficient way for you to manage your event data--whether to consider Elevent or Airtable the ultimate source of truth. You'll want to make a firm choice so you don't run the risk of overwriting changes made in Elevent.