If PSG have changed their mind about Mourinho then Nagelsmann might be the one to take over. People want to see Zidane managing PSG very much but I don't feel like this will happen. Because there isn't even a rumour I have heard of in the recent times. It looks like Zidane is still not keen on managing a team other than a national team he would like. If he signed for PSG now I would have nearly zero doubt left about PSG's future. Despite the solid players leaving the team one by one I would still believe in him to find a way.
By the way I have also heard about Luis Enrique rumour. If we compare him to Nagelsmann he has a more impressive career surely.
There is no clear agreement between PSG and Julian Nagelsmann, we don't even know the reason for Nagelsmann's cancellation of training PSG. but what is certain, the joint decision was made by Nagelsmann and PSG because they did not agree on important details. that means, Nagelsmann is no longer PSG's top priority. regarding Zidane, previously he had conveyed through his side that no agreement had been made whatsoever, Zidane was not at all interested in becoming a PSG coach.
Well, the unique thing is, Mourinho's name is still involved with PSG. even though in the tweets of Fabrizio Romano or other news media, they did not even mention Jose Mourinho's name "after he failed to win the Europa League trophy".
Now, the latest rumors report. Paris Saint-Germain are in advanced talks to appoint Luis Enrique as the new coach - according to L'Equipe. PSG have been more cautious after the Nagelsmann deal fell through but Luis Enrique has come to terms with it. the talk now is about the staff and the 'no momentar' clause from Luis Enrique's side, as Fabrizio Romano quotes. very interesting, we will see how it develops and if these rumors are true. if so, there's nothing wrong with bringing Enrique to the Parc de Princes. but to be honest, ideally I prefer if the PSG squad is under Julian Nagelsmann IMO. at least, can start PSG with lots of young talents. even so, we'll see further developments.