Right, but this was never discussed in the book, so as to remove the eagle plot hole. But one could see it that way. Perhaps galdolf never brought it up, because he only had a gut feeling gollum would have a role to play, and that frodo wouldn't be able to rid himself of the ring anyway...?
Gandalf's hunch was more of a faith-in-all-people kind of thing, IMO. That it turned out he was right twice (Gollum guided them into Mordor and was instrumental in destroying the Ring) really doesn't count that much in my opinion.
