Yes but at that altitude their orbital period is about 1/2 that of low orbits, meaning that even if two orbits do cross paths, there would be fewer potential collisions in a given time. They are 'slower' in relation to size of the sphere they occupy.
I guess that makes sense since the Earth’s radius is around 6400km so from 400 to 1400km is really a change from 6800 to 7800km which is proportionally similar to a change from 90 to 110 minutes.
