It helps, but for those of us who hit it fat now and then, the line quickly becomes a long one.
I wouldn't call a pro that tells you you shouldn't take a divot a pro. He's either lying to save his grass, or seriously misinformed.
I can't replace any divots on the practice range since the turf is too frail. The divots are more a could of dirt and grass than a single object. Does replacing divots help on a driving range? I've heard some say that replacing a divot means the damage will take longer to heal, since the roots won't re-attach anyways. Some courses I've been to has had posters telling players to not replace divots on the course because of this.
I suppose it would be possible to replace divots and have other players hit off it again on a range with good grass, but I didn't know it was a thing.
There's no need, or expectoration to replace or repair divots at a driving range. Simply take care to use the range as shown above and you're being courteous and responsible.