Not seeing individual in-room blow dryers being either a virus danger, or removed from the rooms.
The concern in salons is the potential of blowing the virus around, onto others. In one's hotel room, within the reach of the cord,with only your traveling party or portion thereof, a person could reasonably be expected to know of their companions' health.
Yes, coronaviruses exist on surfaces for varying periods of time. That doesn't mean it lives full force on a given surface for the time or time range indicated. It dies (albeit slowly at times) or dissolves or disintesgrates over that time range.
https://www.webmd.com/lung/how-long-covid-19-lives-on-surfaces