It’s Joel Edgerton’s Turn To Be Rumored For ‘Bourne’
First off, they are worried that his name doesn't hold enough weight (yet) to carry such a franchise. Secondly, they like Edgerton for the seemingly toxic role of the Huntsman in Snow White and the Huntsman. Apparently they feel he is a big enough name for that role. Or that Kristen Stewarts brand equity will do most of the heavy lifting there.
If this seems too cut and dry, don't worry. This Vulture piece also bandies about the names McAvoy and LaBeouf. Maybe the new Bourne lead could be played by a host of actors, like that Bob Dylan biopic. Is Cate Blanchett available?