JHB is definitely an interesting possibility, though at the limits of the A321LR's capabilities.

I also don't think A3 are simply thinking of visitors to/from Greece. With their new routes, they could serve as a logical one stop to/from many destinations. This would in turn increase their off-season pax/revenue. I think creating a hub was part of the plan for the new ATH from day one, though terribly executed - despite it's excellent location as entry to Europe from Asia, ME, Africa and Australasia.

A3 also needed to get a premium J in order to compete with the other carriers serving the ME.