Zidane doesn't seem interested in dealing with Man United no matter how hard Man United tries to get his sign I think he will refuse, if he's really interested to handle Man United why didn't he accept it before Ralf Rangnick's offer came. and Currently there is no option for quality coaches who are currently unemployed. It is natural that Mauricio Pochettino, who already has experience in the EPL, is linked to managing in the coming season, even though his achievements are still far below other popular coaches even from zidane.
Pochettino has been linked with Manchester United for a long time ago, as I remembered before Haaland, the pool on this thread put Pochetino as the next MU coach but it hasn't happened. Zidane also ever said doesn't want to be a coach for half session only. the chance still happens in the next session, that possibility between both (PSG or MU), but for Pochetino, Newcastle still wants him, before to PSG he was linked to Newcastle. he certainly doesn't want to mess around with gossip close to MU.
As far as I know, Zidane rejected Man United's offer at that time because he wanted to rest until the summer of 2022 and his wife did not want to stay at Man United. The chances of Man United being able to sign Zidane are very small because it seems that Zidane will still stick to his stance.
Apart from Mauricio Pochettino, other coach candidates being targeted by Man United are Erik Ten Hag, Julen Lopetegui, and Luis Enrique.
https://twitter.com/David_Ornstein/status/1485525496314187777