It's not going to mark all papers all the time. It will leave indents where the pinch rollers clamp the paper on some media, usually soft natural fibres such as cotton. This is not a new thing, but perhaps with the 79+9900 the pinch wheels are placed at a more inward placement than the older series.
For most prints that are cut down it doesn't make much difference other than waste materials depending on the intervals of time of idle, paper in feed path cycles, and the media type of course.