As usual, as "consensus" of this kind rises a strong suspicion of lots of crackpot pseudoscience being involved. For example, one of the previously linked articles claimed that sweating is a major reason of bone loss during cycling exercise. That article is immediately dismissed a crackpot hogwash, since it fails to explain how is sweating from cycling is different from sweating from any other kind of exercise (with regard to mineral loss at least).

Now let's bring some sense into this.

The bones in the upper body experience the same amount of load while road cycling as they do in other types of exercises that do not involve significant vertical inertial loads (walking being one example). The distribution of that load might differ depending on your riding posture. Obviously, loads experienced by more upright riders will be closer to what is experienced during ordinary walking. Needless to say, cycling styles that do involve significant vertical inertial loads, like mountain biking and cyclocross (just to name a few), might prove to be much better upper-body bone-strengthening exercises than walking or running.

Now for the legs. The bones in your upper leg work differently than when you are walking, of course. When pedaling, the upper leg bones experience side loads mostly. The lower leg bones, on the other hand, experience significant length-wise loads. Under these circumstances, you should expect cycling to be beneficial to strengthening your lower leg bones (as much as these bones can be strengthened by periodic-loading type of exercise).