It comes as something of a surprise, as both Damon and Greengrass have said on the record that they had no plans to revisit a story they felt they had already told. But then, they have both also mooted a potential return if the right script could be written and they could work together again, and it appears that that is certainly the case now.
Universal Pictures, which has yet to officially confirm anything, is apparently so enthused by the idea of the pair returning that it wants them to have the film ready for the 15 July 2016 release date that had previously been given to the Bourne Legacy (2012) follow-up that Justin Lin (Fast & Furious 6) was developing to direct. That film apparently remains in development, so it could well appear after the latest Damon outing, assuming this all actually goes ahead. Lin, meanwhile, may take the opportunity to work on True Detective's second season, which he has also been linked to.
As always, watch this space.