A ceiling fan will modulate the air and effect the sound quality. How much? That's for you to figure out. It may not be an issue for many.
Several years ago, a piano tuner (I only use tuners that tune by ear, not with a machine) was over to tune my Steinway. After a few hours he was pulling out his hair; could not get the job done. I noticed the ceiling fan was on. Just for the heck of it, I turned off the ceiling fan. He finished the job in about 15 minutes. So there you have it.