The possibility that his feelings are now gone is a lot more likely.
If he is talking less to you, that would normally indicate a lack of interest or very lukewarm interest.
Even though he may be a shy guy, the both of you have already confessed your feelings for each other.
Normally, once a shy guy who also happens to be an ambivert gets this far, he will feel a lot more encouraged to ask the girl out on a date and follow through.
So far, he has mentioned going out to a movie but never followed through.
Oftentimes, this is an indication that the guy is not looking to spend any quality time with the girl in real life.
He may have lost his feelings for you when he realized that he would actually have to take the next step and go out with you in real life.
Sometimes, the prospect of taking an online relationship into a real life meeting can be too intimidating for some guys.
This being said, he may still reach out to you on Facebook from time to time.
But, he will only want to chat on a frivolous level and nothing more.