With all the accumulated praise and hate IGA has gotten over the years, he's a Castlevania veteran and has acted accordingly. Not all the games were great, but he addressed criticism in a way that acknowledged he was paying attention to what fans of this series were saying. He was the face of the series for some time, like it or not. Cox doesn't even want that, so I'd say he is unlikely to be cried after, at least not in the way IGA is.
I wouldn't want him completely out of the picture. I'd like it if he focused on the strong points of his work and maybe acted as an advisor, mentor-kind of figure to someone who would continue the Akumajou (*sigh* I hate having to resort to this franchise branching crap, but under the circumstances it's the prudent way of talking about the original timeline..) series. Preferrably someone Japanese. That way he could focus more on what ever he feels like doing now, but still pass his experience on and contribute to the future of Castlevania.
I know he really cares about Castlevania - especially since he respected the work of those before him (*cough* which is an attitude certain people could take a lesson from *cough*) and he has experience. Those are good enough reasons for me to like the idea of him still working on the series. That, and he procuced some great Castlevanias. If he personally does not like the idea, I can't really blame him.