I wouldn't have thought "Do you mind changing your plans?" had anything to do with working for the company in the long term.
It would have more to do with being flexible and having the ability to quickly assess the situation you are faced with, accept that the perfect traffic plan in your head has gone to rats@@t, and come up with another one. Happens to me all the time.
Plans in ATC mean how to sort out the traffic you are presented with in the best possible way.