Pogba is perfectly fine at Juve.
But his staff (Raiola) is clearly delaying his contract renewal. They are clearly playing Marotta.
They want to wait for the WC. With Pogba's explosion at the WC, they'll want either a crazy salary extension - maybe higher than 5M after taxes - or to force a transfer this summer.
IMO we'll be lucky if Pogba remains with us for more 2/3 years. PSG is probably pushing Raiola very high. If Raiola simply rejects the offer proposal after the WC, which is very possible, than Juve will be forced to sell him. We'll get around 50M for him in this situation I guess.
If he renews, in 2 or 3 years PSG, Madrid and City will come knocking again, and he'll leave then. No way he's staying with us for more that 3 years IMO. If he does for more 3 years it'll be excellent.