Here is my foolish, theory/prediction on a ressurected itachi.
Kabuto won't impede itachi's free will at all, except just enough to ensure he doesn't turn on kabuto.
Itachi is a shiny gun to win madara's favor, but the real importance of itachi, is to break madara's spell on sasuke.
Suppose for a moment the uchiha massacre went as follows:
Madara killed the uchiha clan, Danzou and the Anbu (including Itachi) responded to the attack to find everyone dead. Madara couldn't kill Itachi because itachi had too much backup with him. Madara escaped from the anbu, and who should be comming home but sasuke.
Itachi says he has to find justice for his clan's murder, but to do so, will mean abandoning the last member of his clan.
The culprit matches the description of the man who attacked the 4th durring the fox attack 8 years earlier. This can't be a coincidence. at worst it's an organization behind the attacks, at best it's one super powerful ninja, that itachi feels he can deal with if he can get a second chance at him.
Itachi comes up with the plan, that the massacre be blamed on him. It will make him an outcast, and allow him to operate freely in order to find the masked ninja who did this.
So he makes sasuke believe that he killed the entire clan.
But with sasuke's current brother worship, and new found love of his clan, not to mention his insatiable thirst for hate and revenge, this fits in perfectly, and now sasuke, hears from his own brother, what happened, and turns against madara.
This now puts madara in the position of having to fight sasuke, kabuto, and the ninja alliance, with only zetsu, and maybe 100,000 zetsu clones, to back him up.
And if Kabuto is about to make more clones, or work on the exsisting ones, who would want to bet those clones won't be a factor when the time comes.
now Kabuto, could also take possession of several sharingans from madara's lab, and maybe even the rinnenegan.
He could theoretically pass them down through incarnations for the rest of his immortal life, if he uses orochimaru's body swapping jutsu.