If you see in the official website, there are lot more articles, speculation news, photos of Samir Nasri in training etc. Sami Nasri is transfer-listed by the club.
You hardly find such things about Hart in the website. Also mancity twitter tags Nasri, or other players if it tweets about them. No tags for Hart. I would imagine something has happened behind closed doors, which has triggered the dropping of Hart & pursuit of Bravo so late. Most likely, Hart has defied Pep openly in training or his ideas or his other player rules. And Pep is only tolerating coz Hart is a city legend. Also, the way Pep said he has an excellent relationship with Hart, he is clear with him & vice versa, was more sarcasm and a reflection that Hart openly rebels and Pep openly says he wont tolerate it? I think in Pep's eyes, if it was anybody else with this behavior, Pep would hv done an Ibra and done a fire-sale. He is allowing Hart to decide his own next step, only bcoz of what he means to City.
This is just me speculating, hope I'm wrong for City's sake.