Matt Damon has stated that he will NOT return to the series without previous director Greengrass, but I think Gilroy has enough clout to lure the actor back. If not, then the Bourne films will suffer in my opinion.
Any casting suggestion for a new Jason Bourne?
Only Damon can play bourne. There is no substitute for him, he captures bourne so well.
Matt does an exquisite job in this role. I hope he comes back for it even though there will be a different director.
If not, maybe Christian Bale, Jake Gyllenhaal, or Tahmoh Penikett.