Undoubtedly Mourinho has been discussing with Roman behind the scenes how he would want things, hopefully imparting some managerial wisdom in the process. He could easily point to some of the club's weaknesses such as how not giving managers enough time acts as a major disincentive for bringing through young players, which given the massive investment in youth, is basically equivalent to shooting yourself in the foot. Or how the manager must be free to build his squad, and not have unwanted vanity signings foisted upon him. Or how managers, especially those of teams in transition such as ours, must be not be judged over a course of a few weeks, but over a few seasons.
Even if Roman is not prepared to compromise on these above points, or not prepared to offer an attractive enough compensation package, and JM signs for PSG, at the very least he would do well to listen and learn.