I think this kind of a post is too personal to place on somebody's wall without asking first. You could have messaged it to him privately and I am sure he would have appreciated it. The deactivation does seem to be a gross overreaction. If he did delete it but would not confirm that to you, I would not call it lying; he might have been embarrassed and did not know how to tell you that you were not welcome to post private messages publicly because he was afraid of hurting your feelings. I would not be surprised if he changes his settings to disallow posts on his wall by anybody other than him.

I would reactivate the FB account but draw a clear boundary between the public and the private messages.

If the bf is proud to have you, he can reveal it by making you his relationship partner on FB - there is such an option. Public love confessions on his wall... on the wedding day they would be appropriate for sure, but now... better stick to PM's.

The bf DOES sound super sweet and I would never mention this incident to him again.