Cyclists at risk for bone loss

That's maybe a bit extreme, I'm sure the threshold for fracture would be reached with that kind of repeated loading. Will certainly be true of a track athlete though.

Not so, it creates lots of micro traumas and the body responds by making the bone much much stronger.

But thats not the issue at hand here. Lots of weight training & running will not rule out these bone weakening issues for 'proper cyclists' as in ones who do long races and a re sweating for hours on end.

Its to do with mineral loss mostly. So adjusting diet/taking supplements is what is needed and of course regular impact exercise will help too.