Not true really, ASTOR cant do the job the MR2 does and visa-versa. It could be argued that there isn't any other platform that can do what the MR2 is capable of.
ASTOR is a way off being deployed yet as it will take a while for aircrews/groundcrews to get to know the plane. Maybe next year if we are lucky, but again, it wont replace the MR2.