Addons with iCal functionality

There are two addons in the marketplace providing iCal functionality:
Import / Export data
Social Media Share

However, from what I can see (and also checking the demo for Import / Export data), it seems the ICS file that the link provides is a one-time download and not a link to an ICS file that is maintained, i.e.: what happens if there is a new event? Does the user have to redownload the ICS? Or is the ICS updated automatically?

Thanks