No idea, it’s really difficult to predict what Priest has planned for this story. But one thing I’m sure of whatever will happen, Damian is Bruce’s bio son.
Poor Damian though, first in the wedding prelude his grandfather tried to lure him into the thought of being replaced by Bruce’s bio kid with Selina. Now, this Robin (whoever it was) tried to say to Damian that he’s not Bruce’s bio son and that he knew of his “real” father?? Boy can’t take a rest for sure.