I don't think they will or won't get married. But if they do, I don't think it will be in a movie. Think of how much a wedding would slow the pace of the film down.
In TPM, there were ver few times when Lucas slowed things down, I certainly don't think he'll do it for a 20 minute ceremony. Even if he cuts the ceremony to the important parts.
Of course, it could be the last scene of AotC 😕 They get married, knowing that Padme is pregnant!