This seems a troubling result. Ultimately, we will be able to see that the CI may not entail it. But this is still pretty metaphorical, we need a clearer interpretation. Before we proceed, however, we might consider how Kant proposes to ground the CI's second formulation.
Moral imperatives are categorical imperatives.
The possibility of a categorical imperative depends on there being some end which is essential to practical reason. The only possible such end is rational nature itself. Rational nature would have to be an end in itself in that it would have to be its own end. Rational nature exists as an end in itself. There can be categorical imperatives only if rational nature is an end in itself.